[CodeGen] Complete machine pass and ABI lowering infrastructure

8 files changed, 1763 insertions, 0 deletions

diff --git a/backend/include/rcc/CodeGen/GenericOpcode.def b/backend/include/rcc/CodeGen/GenericOpcode.def
new file mode 100644
index 0000000..8caaf7b
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GenericOpcode.def
@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// This file is intentionally included multiple times. Define
+// RCC_CORE_OPCODE and RCC_GENERIC_OPCODE before including it.
+
+RCC_CORE_OPCODE(PHI)
+RCC_CORE_OPCODE(INLINEASM)
+RCC_CORE_OPCODE(INLINEASM_BR)
+RCC_CORE_OPCODE(CFI_INSTRUCTION)
+RCC_CORE_OPCODE(EH_LABEL)
+RCC_CORE_OPCODE(GC_LABEL)
+RCC_CORE_OPCODE(ANNOTATION_LABEL)
+RCC_CORE_OPCODE(KILL)
+RCC_CORE_OPCODE(EXTRACT_SUBREG)
+RCC_CORE_OPCODE(INSERT_SUBREG)
+RCC_CORE_OPCODE(IMPLICIT_DEF)
+RCC_CORE_OPCODE(INIT_UNDEF)
+RCC_CORE_OPCODE(SUBREG_TO_REG)
+RCC_CORE_OPCODE(COPY_TO_REGCLASS)
+RCC_CORE_OPCODE(DBG_VALUE)
+RCC_CORE_OPCODE(DBG_VALUE_LIST)
+RCC_CORE_OPCODE(DBG_INSTR_REF)
+RCC_CORE_OPCODE(DBG_PHI)
+RCC_CORE_OPCODE(DBG_LABEL)
+RCC_CORE_OPCODE(REG_SEQUENCE)
+RCC_CORE_OPCODE(COPY)
+RCC_CORE_OPCODE(COPY_LANEMASK)
+RCC_CORE_OPCODE(BUNDLE)
+RCC_CORE_OPCODE(LIFETIME_START)
+RCC_CORE_OPCODE(LIFETIME_END)
+RCC_CORE_OPCODE(PSEUDO_PROBE)
+RCC_CORE_OPCODE(ARITH_FENCE)
+RCC_CORE_OPCODE(STACKMAP)
+RCC_CORE_OPCODE(FENTRY_CALL)
+RCC_CORE_OPCODE(PATCHPOINT)
+RCC_CORE_OPCODE(LOAD_STACK_GUARD)
+RCC_CORE_OPCODE(PREALLOCATED_SETUP)
+RCC_CORE_OPCODE(PREALLOCATED_ARG)
+RCC_CORE_OPCODE(STATEPOINT)
+RCC_CORE_OPCODE(LOCAL_ESCAPE)
+RCC_CORE_OPCODE(FAULTING_OP)
+RCC_CORE_OPCODE(PATCHABLE_OP)
+RCC_CORE_OPCODE(PATCHABLE_FUNCTION_ENTER)
+RCC_CORE_OPCODE(PATCHABLE_RET)
+RCC_CORE_OPCODE(PATCHABLE_FUNCTION_EXIT)
+RCC_CORE_OPCODE(PATCHABLE_TAIL_CALL)
+RCC_CORE_OPCODE(PATCHABLE_EVENT_CALL)
+RCC_CORE_OPCODE(PATCHABLE_TYPED_EVENT_CALL)
+RCC_CORE_OPCODE(ICALL_BRANCH_FUNNEL)
+RCC_CORE_OPCODE(FAKE_USE)
+RCC_CORE_OPCODE(MEMBARRIER)
+RCC_CORE_OPCODE(JUMP_TABLE_DEBUG_INFO)
+RCC_CORE_OPCODE(RELOC_NONE)
+RCC_CORE_OPCODE(CONVERGENCECTRL_ENTRY)
+RCC_CORE_OPCODE(CONVERGENCECTRL_ANCHOR)
+RCC_CORE_OPCODE(CONVERGENCECTRL_LOOP)
+RCC_CORE_OPCODE(CONVERGENCECTRL_GLUE)
+
+RCC_GENERIC_OPCODE(G_ASSERT_SEXT)
+RCC_GENERIC_OPCODE(G_ASSERT_ZEXT)
+RCC_GENERIC_OPCODE(G_ASSERT_ALIGN)
+RCC_GENERIC_OPCODE(G_ADD)
+RCC_GENERIC_OPCODE(G_SUB)
+RCC_GENERIC_OPCODE(G_MUL)
+RCC_GENERIC_OPCODE(G_SDIV)
+RCC_GENERIC_OPCODE(G_UDIV)
+RCC_GENERIC_OPCODE(G_SREM)
+RCC_GENERIC_OPCODE(G_UREM)
+RCC_GENERIC_OPCODE(G_SDIVREM)
+RCC_GENERIC_OPCODE(G_UDIVREM)
+RCC_GENERIC_OPCODE(G_AND)
+RCC_GENERIC_OPCODE(G_OR)
+RCC_GENERIC_OPCODE(G_XOR)
+RCC_GENERIC_OPCODE(G_ABDS)
+RCC_GENERIC_OPCODE(G_ABDU)
+RCC_GENERIC_OPCODE(G_UAVGFLOOR)
+RCC_GENERIC_OPCODE(G_UAVGCEIL)
+RCC_GENERIC_OPCODE(G_SAVGFLOOR)
+RCC_GENERIC_OPCODE(G_SAVGCEIL)
+RCC_GENERIC_OPCODE(G_IMPLICIT_DEF)
+RCC_GENERIC_OPCODE(G_PHI)
+RCC_GENERIC_OPCODE(G_FRAME_INDEX)
+RCC_GENERIC_OPCODE(G_GLOBAL_VALUE)
+RCC_GENERIC_OPCODE(G_PTRAUTH_GLOBAL_VALUE)
+RCC_GENERIC_OPCODE(G_CONSTANT_POOL)
+RCC_GENERIC_OPCODE(G_EXTRACT)
+RCC_GENERIC_OPCODE(G_UNMERGE_VALUES)
+RCC_GENERIC_OPCODE(G_INSERT)
+RCC_GENERIC_OPCODE(G_MERGE_VALUES)
+RCC_GENERIC_OPCODE(G_BUILD_VECTOR)
+RCC_GENERIC_OPCODE(G_BUILD_VECTOR_TRUNC)
+RCC_GENERIC_OPCODE(G_CONCAT_VECTORS)
+RCC_GENERIC_OPCODE(G_PTRTOINT)
+RCC_GENERIC_OPCODE(G_INTTOPTR)
+RCC_GENERIC_OPCODE(G_BITCAST)
+RCC_GENERIC_OPCODE(G_FREEZE)
+RCC_GENERIC_OPCODE(G_CONSTANT_FOLD_BARRIER)
+RCC_GENERIC_OPCODE(G_INTRINSIC_FPTRUNC_ROUND)
+RCC_GENERIC_OPCODE(G_INTRINSIC_TRUNC)
+RCC_GENERIC_OPCODE(G_INTRINSIC_ROUND)
+RCC_GENERIC_OPCODE(G_INTRINSIC_LRINT)
+RCC_GENERIC_OPCODE(G_INTRINSIC_LLRINT)
+RCC_GENERIC_OPCODE(G_INTRINSIC_ROUNDEVEN)
+RCC_GENERIC_OPCODE(G_READCYCLECOUNTER)
+RCC_GENERIC_OPCODE(G_READSTEADYCOUNTER)
+RCC_GENERIC_OPCODE(G_LOAD)
+RCC_GENERIC_OPCODE(G_SEXTLOAD)
+RCC_GENERIC_OPCODE(G_ZEXTLOAD)
+RCC_GENERIC_OPCODE(G_FPEXTLOAD)
+RCC_GENERIC_OPCODE(G_INDEXED_LOAD)
+RCC_GENERIC_OPCODE(G_INDEXED_SEXTLOAD)
+RCC_GENERIC_OPCODE(G_INDEXED_ZEXTLOAD)
+RCC_GENERIC_OPCODE(G_STORE)
+RCC_GENERIC_OPCODE(G_FPTRUNCSTORE)
+RCC_GENERIC_OPCODE(G_INDEXED_STORE)
+RCC_GENERIC_OPCODE(G_ATOMIC_CMPXCHG_WITH_SUCCESS)
+RCC_GENERIC_OPCODE(G_ATOMIC_CMPXCHG)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_XCHG)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_ADD)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_SUB)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_AND)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_NAND)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_OR)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_XOR)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_MAX)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_MIN)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_UMAX)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_UMIN)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FADD)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FSUB)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMAX)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMIN)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMAXIMUM)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMINIMUM)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMAXIMUMNUM)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_FMINIMUMNUM)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_UINC_WRAP)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_UDEC_WRAP)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_USUB_COND)
+RCC_GENERIC_OPCODE(G_ATOMICRMW_USUB_SAT)
+RCC_GENERIC_OPCODE(G_FENCE)
+RCC_GENERIC_OPCODE(G_PREFETCH)
+RCC_GENERIC_OPCODE(G_BRCOND)
+RCC_GENERIC_OPCODE(G_BRINDIRECT)
+RCC_GENERIC_OPCODE(G_INVOKE_REGION_START)
+RCC_GENERIC_OPCODE(G_INTRINSIC)
+RCC_GENERIC_OPCODE(G_INTRINSIC_W_SIDE_EFFECTS)
+RCC_GENERIC_OPCODE(G_INTRINSIC_CONVERGENT)
+RCC_GENERIC_OPCODE(G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS)
+RCC_GENERIC_OPCODE(G_ANYEXT)
+RCC_GENERIC_OPCODE(G_TRUNC)
+RCC_GENERIC_OPCODE(G_TRUNC_SSAT_S)
+RCC_GENERIC_OPCODE(G_TRUNC_SSAT_U)
+RCC_GENERIC_OPCODE(G_TRUNC_USAT_U)
+RCC_GENERIC_OPCODE(G_CONSTANT)
+RCC_GENERIC_OPCODE(G_FCONSTANT)
+RCC_GENERIC_OPCODE(G_VASTART)
+RCC_GENERIC_OPCODE(G_VAARG)
+RCC_GENERIC_OPCODE(G_SEXT)
+RCC_GENERIC_OPCODE(G_SEXT_INREG)
+RCC_GENERIC_OPCODE(G_ZEXT)
+RCC_GENERIC_OPCODE(G_SHL)
+RCC_GENERIC_OPCODE(G_LSHR)
+RCC_GENERIC_OPCODE(G_ASHR)
+RCC_GENERIC_OPCODE(G_FSHL)
+RCC_GENERIC_OPCODE(G_FSHR)
+RCC_GENERIC_OPCODE(G_ROTR)
+RCC_GENERIC_OPCODE(G_ROTL)
+RCC_GENERIC_OPCODE(G_ICMP)
+RCC_GENERIC_OPCODE(G_FCMP)
+RCC_GENERIC_OPCODE(G_SCMP)
+RCC_GENERIC_OPCODE(G_UCMP)
+RCC_GENERIC_OPCODE(G_SELECT)
+RCC_GENERIC_OPCODE(G_UADDO)
+RCC_GENERIC_OPCODE(G_UADDE)
+RCC_GENERIC_OPCODE(G_USUBO)
+RCC_GENERIC_OPCODE(G_USUBE)
+RCC_GENERIC_OPCODE(G_SADDO)
+RCC_GENERIC_OPCODE(G_SADDE)
+RCC_GENERIC_OPCODE(G_SSUBO)
+RCC_GENERIC_OPCODE(G_SSUBE)
+RCC_GENERIC_OPCODE(G_UMULO)
+RCC_GENERIC_OPCODE(G_SMULO)
+RCC_GENERIC_OPCODE(G_UMULH)
+RCC_GENERIC_OPCODE(G_SMULH)
+RCC_GENERIC_OPCODE(G_UADDSAT)
+RCC_GENERIC_OPCODE(G_SADDSAT)
+RCC_GENERIC_OPCODE(G_USUBSAT)
+RCC_GENERIC_OPCODE(G_SSUBSAT)
+RCC_GENERIC_OPCODE(G_USHLSAT)
+RCC_GENERIC_OPCODE(G_SSHLSAT)
+RCC_GENERIC_OPCODE(G_SMULFIX)
+RCC_GENERIC_OPCODE(G_UMULFIX)
+RCC_GENERIC_OPCODE(G_SMULFIXSAT)
+RCC_GENERIC_OPCODE(G_UMULFIXSAT)
+RCC_GENERIC_OPCODE(G_SDIVFIX)
+RCC_GENERIC_OPCODE(G_UDIVFIX)
+RCC_GENERIC_OPCODE(G_SDIVFIXSAT)
+RCC_GENERIC_OPCODE(G_UDIVFIXSAT)
+RCC_GENERIC_OPCODE(G_FADD)
+RCC_GENERIC_OPCODE(G_FSUB)
+RCC_GENERIC_OPCODE(G_FMUL)
+RCC_GENERIC_OPCODE(G_FMA)
+RCC_GENERIC_OPCODE(G_FMAD)
+RCC_GENERIC_OPCODE(G_FDIV)
+RCC_GENERIC_OPCODE(G_FREM)
+RCC_GENERIC_OPCODE(G_FMODF)
+RCC_GENERIC_OPCODE(G_FPOW)
+RCC_GENERIC_OPCODE(G_FPOWI)
+RCC_GENERIC_OPCODE(G_FEXP)
+RCC_GENERIC_OPCODE(G_FEXP2)
+RCC_GENERIC_OPCODE(G_FEXP10)
+RCC_GENERIC_OPCODE(G_FLOG)
+RCC_GENERIC_OPCODE(G_FLOG2)
+RCC_GENERIC_OPCODE(G_FLOG10)
+RCC_GENERIC_OPCODE(G_FLDEXP)
+RCC_GENERIC_OPCODE(G_FFREXP)
+RCC_GENERIC_OPCODE(G_FNEG)
+RCC_GENERIC_OPCODE(G_FPEXT)
+RCC_GENERIC_OPCODE(G_FPTRUNC)
+RCC_GENERIC_OPCODE(G_FPTOSI)
+RCC_GENERIC_OPCODE(G_FPTOUI)
+RCC_GENERIC_OPCODE(G_SITOFP)
+RCC_GENERIC_OPCODE(G_UITOFP)
+RCC_GENERIC_OPCODE(G_FPTOSI_SAT)
+RCC_GENERIC_OPCODE(G_FPTOUI_SAT)
+RCC_GENERIC_OPCODE(G_FABS)
+RCC_GENERIC_OPCODE(G_FCOPYSIGN)
+RCC_GENERIC_OPCODE(G_IS_FPCLASS)
+RCC_GENERIC_OPCODE(G_FCANONICALIZE)
+RCC_GENERIC_OPCODE(G_FMINNUM)
+RCC_GENERIC_OPCODE(G_FMAXNUM)
+RCC_GENERIC_OPCODE(G_FMINNUM_IEEE)
+RCC_GENERIC_OPCODE(G_FMAXNUM_IEEE)
+RCC_GENERIC_OPCODE(G_FMINIMUM)
+RCC_GENERIC_OPCODE(G_FMAXIMUM)
+RCC_GENERIC_OPCODE(G_FMINIMUMNUM)
+RCC_GENERIC_OPCODE(G_FMAXIMUMNUM)
+RCC_GENERIC_OPCODE(G_GET_FPENV)
+RCC_GENERIC_OPCODE(G_SET_FPENV)
+RCC_GENERIC_OPCODE(G_RESET_FPENV)
+RCC_GENERIC_OPCODE(G_GET_FPMODE)
+RCC_GENERIC_OPCODE(G_SET_FPMODE)
+RCC_GENERIC_OPCODE(G_RESET_FPMODE)
+RCC_GENERIC_OPCODE(G_GET_ROUNDING)
+RCC_GENERIC_OPCODE(G_SET_ROUNDING)
+RCC_GENERIC_OPCODE(G_PTR_ADD)
+RCC_GENERIC_OPCODE(G_PTRMASK)
+RCC_GENERIC_OPCODE(G_SMIN)
+RCC_GENERIC_OPCODE(G_SMAX)
+RCC_GENERIC_OPCODE(G_UMIN)
+RCC_GENERIC_OPCODE(G_UMAX)
+RCC_GENERIC_OPCODE(G_ABS)
+RCC_GENERIC_OPCODE(G_LROUND)
+RCC_GENERIC_OPCODE(G_LLROUND)
+RCC_GENERIC_OPCODE(G_BR)
+RCC_GENERIC_OPCODE(G_BRJT)
+RCC_GENERIC_OPCODE(G_VSCALE)
+RCC_GENERIC_OPCODE(G_INSERT_SUBVECTOR)
+RCC_GENERIC_OPCODE(G_EXTRACT_SUBVECTOR)
+RCC_GENERIC_OPCODE(G_INSERT_VECTOR_ELT)
+RCC_GENERIC_OPCODE(G_EXTRACT_VECTOR_ELT)
+RCC_GENERIC_OPCODE(G_SHUFFLE_VECTOR)
+RCC_GENERIC_OPCODE(G_SPLAT_VECTOR)
+RCC_GENERIC_OPCODE(G_STEP_VECTOR)
+RCC_GENERIC_OPCODE(G_VECTOR_COMPRESS)
+RCC_GENERIC_OPCODE(G_CTTZ)
+RCC_GENERIC_OPCODE(G_CTTZ_ZERO_POISON)
+RCC_GENERIC_OPCODE(G_CTLZ)
+RCC_GENERIC_OPCODE(G_CTLZ_ZERO_POISON)
+RCC_GENERIC_OPCODE(G_CTLS)
+RCC_GENERIC_OPCODE(G_CTPOP)
+RCC_GENERIC_OPCODE(G_BSWAP)
+RCC_GENERIC_OPCODE(G_BITREVERSE)
+RCC_GENERIC_OPCODE(G_CLMUL)
+RCC_GENERIC_OPCODE(G_FCEIL)
+RCC_GENERIC_OPCODE(G_FCOS)
+RCC_GENERIC_OPCODE(G_FSIN)
+RCC_GENERIC_OPCODE(G_FSINCOS)
+RCC_GENERIC_OPCODE(G_FTAN)
+RCC_GENERIC_OPCODE(G_FACOS)
+RCC_GENERIC_OPCODE(G_FASIN)
+RCC_GENERIC_OPCODE(G_FATAN)
+RCC_GENERIC_OPCODE(G_FATAN2)
+RCC_GENERIC_OPCODE(G_FCOSH)
+RCC_GENERIC_OPCODE(G_FSINH)
+RCC_GENERIC_OPCODE(G_FTANH)
+RCC_GENERIC_OPCODE(G_FSQRT)
+RCC_GENERIC_OPCODE(G_FFLOOR)
+RCC_GENERIC_OPCODE(G_FRINT)
+RCC_GENERIC_OPCODE(G_FNEARBYINT)
+RCC_GENERIC_OPCODE(G_ADDRSPACE_CAST)
+RCC_GENERIC_OPCODE(G_BLOCK_ADDR)
+RCC_GENERIC_OPCODE(G_JUMP_TABLE)
+RCC_GENERIC_OPCODE(G_DYN_STACKALLOC)
+RCC_GENERIC_OPCODE(G_STACKSAVE)
+RCC_GENERIC_OPCODE(G_STACKRESTORE)
+RCC_GENERIC_OPCODE(G_STRICT_FADD)
+RCC_GENERIC_OPCODE(G_STRICT_FSUB)
+RCC_GENERIC_OPCODE(G_STRICT_FMUL)
+RCC_GENERIC_OPCODE(G_STRICT_FDIV)
+RCC_GENERIC_OPCODE(G_STRICT_FREM)
+RCC_GENERIC_OPCODE(G_STRICT_FMA)
+RCC_GENERIC_OPCODE(G_STRICT_FSQRT)
+RCC_GENERIC_OPCODE(G_STRICT_FLDEXP)
+RCC_GENERIC_OPCODE(G_STRICT_FCMP)
+RCC_GENERIC_OPCODE(G_STRICT_FCMPS)
+RCC_GENERIC_OPCODE(G_READ_REGISTER)
+RCC_GENERIC_OPCODE(G_WRITE_REGISTER)
+RCC_GENERIC_OPCODE(G_MEMCPY)
+RCC_GENERIC_OPCODE(G_MEMCPY_INLINE)
+RCC_GENERIC_OPCODE(G_MEMMOVE)
+RCC_GENERIC_OPCODE(G_MEMSET)
+RCC_GENERIC_OPCODE(G_BZERO)
+RCC_GENERIC_OPCODE(G_TRAP)
+RCC_GENERIC_OPCODE(G_DEBUGTRAP)
+RCC_GENERIC_OPCODE(G_UBSANTRAP)
+RCC_GENERIC_OPCODE(G_VECREDUCE_SEQ_FADD)
+RCC_GENERIC_OPCODE(G_VECREDUCE_SEQ_FMUL)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FADD)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FMUL)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FMAX)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FMIN)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FMAXIMUM)
+RCC_GENERIC_OPCODE(G_VECREDUCE_FMINIMUM)
+RCC_GENERIC_OPCODE(G_VECREDUCE_ADD)
+RCC_GENERIC_OPCODE(G_VECREDUCE_MUL)
+RCC_GENERIC_OPCODE(G_VECREDUCE_AND)
+RCC_GENERIC_OPCODE(G_VECREDUCE_OR)
+RCC_GENERIC_OPCODE(G_VECREDUCE_XOR)
+RCC_GENERIC_OPCODE(G_VECREDUCE_SMAX)
+RCC_GENERIC_OPCODE(G_VECREDUCE_SMIN)
+RCC_GENERIC_OPCODE(G_VECREDUCE_UMAX)
+RCC_GENERIC_OPCODE(G_VECREDUCE_UMIN)
+RCC_GENERIC_OPCODE(G_SBFX)
+RCC_GENERIC_OPCODE(G_UBFX)
diff --git a/backend/include/rcc/CodeGen/GenericOpcodes.h b/backend/include/rcc/CodeGen/GenericOpcodes.h
new file mode 100644
index 0000000..5a46e21
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GenericOpcodes.h
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GENERICOPCODES_H
+#define RCC_CODEGEN_GENERICOPCODES_H
+
+#include "rcc/CodeGen/InstructionDescriptor.h"
+
+#include <cstdint>
+#include <span>
+#include <string_view>
+#include <vector>
+
+namespace rcc {
+
+// Target-independent values are build-local. Target tables start at 1024 and
+// are appended to this set when a target description is constructed.
+enum class GenericOpcode : std::uint32_t {
+  Invalid,
+#define RCC_CORE_OPCODE(Name) Name,
+#define RCC_GENERIC_OPCODE(Name)
+#include "rcc/CodeGen/GenericOpcode.def"
+#undef RCC_GENERIC_OPCODE
+#undef RCC_CORE_OPCODE
+  CORE_PSEUDO_END,
+
+#define RCC_CORE_OPCODE(Name)
+#define RCC_GENERIC_OPCODE(Name) Name,
+#include "rcc/CodeGen/GenericOpcode.def"
+#undef RCC_GENERIC_OPCODE
+#undef RCC_CORE_OPCODE
+  G_GENERIC_END,
+};
+
+[[nodiscard]] constexpr Opcode opcode(GenericOpcode Generic) noexcept {
+  return Opcode::fromValue(static_cast<std::uint32_t>(Generic));
+}
+
+[[nodiscard]] constexpr bool isGenericOpcode(Opcode Value) noexcept {
+  return Value.value() >= static_cast<std::uint32_t>(GenericOpcode::G_ASSERT_SEXT) &&
+         Value.value() < static_cast<std::uint32_t>(GenericOpcode::G_GENERIC_END);
+}
+
+[[nodiscard]] constexpr bool isCorePseudoOpcode(Opcode Value) noexcept {
+  return Value.value() >= static_cast<std::uint32_t>(GenericOpcode::PHI) &&
+         Value.value() < static_cast<std::uint32_t>(GenericOpcode::CORE_PSEUDO_END);
+}
+
+inline constexpr std::size_t CorePseudoOpcodeCount =
+    static_cast<std::size_t>(GenericOpcode::CORE_PSEUDO_END) -
+    static_cast<std::size_t>(GenericOpcode::PHI);
+
+inline constexpr std::size_t GenericOpcodeCount =
+    static_cast<std::size_t>(GenericOpcode::G_GENERIC_END) -
+    static_cast<std::size_t>(GenericOpcode::G_ASSERT_SEXT);
+
+[[nodiscard]] std::string_view getGenericOpcodeName(GenericOpcode OpcodeValue) noexcept;
+
+[[nodiscard]] std::span<const InstructionDescriptor> genericInstructionDescriptors() noexcept;
+
+[[nodiscard]] std::span<const ImmediatePredicate> genericImmediatePredicates() noexcept;
+
+[[nodiscard]] Expected<void>
+appendGenericInstructionInfo(std::vector<InstructionDescriptor> &Descriptors,
+                             std::vector<ImmediatePredicate> &Predicates);
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GENERICOPCODES_H
diff --git a/backend/include/rcc/CodeGen/MachineAnalyses.h b/backend/include/rcc/CodeGen/MachineAnalyses.h
new file mode 100644
index 0000000..eda550d
--- /dev/null
+++ b/backend/include/rcc/CodeGen/MachineAnalyses.h
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_MACHINEANALYSES_H
+#define RCC_CODEGEN_MACHINEANALYSES_H
+
+#include "rcc/CodeGen/MachineBasicBlock.h"
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/CodeGen/MachinePass.h"
+#include "rcc/CodeGen/StableID.h"
+#include "rcc/Support/Error.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <span>
+#include <string_view>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+namespace rcc {
+
+class MachineBasicBlock;
+class MachineFunction;
+class MachineInstr;
+class MachineMemOperand;
+class TargetDescription;
+
+class MachineDominatorTreeAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] bool isReachable(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] bool dominates(const MachineBasicBlock &Dominator,
+                                 const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] bool dominates(const MachineInstr &Dominator,
+                                 const MachineInstr &Instruction) const noexcept;
+    [[nodiscard]] const MachineBasicBlock *
+    immediateDominator(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] const MachineBasicBlock *
+    nearestCommonDominator(const MachineBasicBlock &Left,
+                           const MachineBasicBlock &Right) const noexcept;
+    [[nodiscard]] std::span<MachineBasicBlock *const> unreachableBlocks() const noexcept {
+      return UnreachableBlocks;
+    }
+
+    [[nodiscard]] Expected<void> updateAfterCFGChange(MachineFunction &Function);
+
+  private:
+    [[nodiscard]] Expected<void> build(MachineFunction &Function);
+
+    std::vector<MachineBasicBlock *> Blocks;
+    std::unordered_map<const MachineBasicBlock *, std::size_t> BlockToIndex;
+    std::vector<std::vector<bool>> Dominators;
+    std::vector<const MachineBasicBlock *> ImmediateDominators;
+    std::vector<bool> Reachable;
+    std::vector<MachineBasicBlock *> UnreachableBlocks;
+
+    friend class MachineDominatorTreeAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineDominatorTree";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+struct MachineLoop final {
+  MachineBasicBlock *Header = nullptr;
+  std::vector<MachineBasicBlock *> Blocks;
+  std::vector<MachineBasicBlock *> Latches;
+  std::size_t Parent = static_cast<std::size_t>(-1);
+  std::vector<std::size_t> Children;
+  std::uint32_t Depth = 1;
+};
+
+struct IrreducibleMachineRegion final {
+  std::vector<MachineBasicBlock *> Blocks;
+  std::vector<MachineBasicBlock *> Entries;
+};
+
+class MachineLoopAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] std::span<const MachineLoop> loops() const noexcept {
+      return Loops;
+    }
+    [[nodiscard]] std::span<const IrreducibleMachineRegion> irreducibleRegions() const noexcept {
+      return IrreducibleRegions;
+    }
+    [[nodiscard]] const MachineLoop *loopFor(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] std::uint32_t loopDepth(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] bool isIrreducible(const MachineBasicBlock &Block) const noexcept;
+
+  private:
+    std::vector<MachineLoop> Loops;
+    std::vector<IrreducibleMachineRegion> IrreducibleRegions;
+    std::unordered_map<const MachineBasicBlock *, std::size_t> InnermostLoop;
+    std::unordered_set<const MachineBasicBlock *> IrreducibleBlocks;
+
+    friend class MachineLoopAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineLoopInfo";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+class MachineBranchProbabilityAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] BranchProbability probability(const MachineBasicBlock &From,
+                                                const MachineBasicBlock &To) const noexcept;
+    [[nodiscard]] std::span<const MachineSuccessor>
+    successors(const MachineBasicBlock &Block) const noexcept;
+
+  private:
+    std::unordered_map<const MachineBasicBlock *, std::vector<MachineSuccessor>> Probabilities;
+
+    friend class MachineBranchProbabilityAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineBranchProbability";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+class MachineBlockFrequencyAnalysis final {
+public:
+  static constexpr std::uint64_t EntryFrequency = std::uint64_t{1} << 32U;
+
+  class Result final {
+  public:
+    [[nodiscard]] std::uint64_t frequency(const MachineBasicBlock &Block) const noexcept;
+
+  private:
+    std::unordered_map<const MachineBasicBlock *, std::uint64_t> Frequencies;
+
+    friend class MachineBlockFrequencyAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineBlockFrequency";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+enum class MachineAliasResult : std::uint8_t {
+  NoAlias,
+  MayAlias,
+  PartialAlias,
+  MustAlias,
+};
+
+class MachineAliasAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] MachineAliasResult alias(const MachineMemOperand &Left,
+                                           const MachineMemOperand &Right) const noexcept;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineAliasAnalysis";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+enum class MachineMemoryDependencyKind : std::uint8_t {
+  Flow,
+  Anti,
+  Output,
+  Ordered,
+};
+
+struct MachineMemoryDependency final {
+  MachineInstrStableID Source;
+  MachineInstrStableID Destination;
+  MachineMemoryDependencyKind Kind = MachineMemoryDependencyKind::Ordered;
+};
+
+struct MachineMemoryDependenceRegion final {
+  const MachineBasicBlock *Block = nullptr;
+  std::vector<MachineInstrStableID> Instructions;
+};
+
+class MachineMemoryDependenceAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] std::span<const MachineMemoryDependenceRegion> regions() const noexcept {
+      return Regions;
+    }
+    [[nodiscard]] const MachineMemoryDependenceRegion *
+    regionFor(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] std::span<const MachineMemoryDependency>
+    dependencies(const MachineBasicBlock &Block) const noexcept;
+    [[nodiscard]] std::span<const MachineMemoryDependency>
+    dependencies(const MachineInstr &Instruction) const noexcept;
+    [[nodiscard]] std::span<const MachineMemoryDependency> allDependencies() const noexcept {
+      return Dependencies;
+    }
+
+  private:
+    struct Range final {
+      std::size_t Begin = 0;
+      std::size_t Size = 0;
+    };
+
+    std::vector<MachineMemoryDependency> Dependencies;
+    std::vector<MachineMemoryDependenceRegion> Regions;
+    std::unordered_map<const MachineBasicBlock *, std::size_t> BlockToRegion;
+    std::unordered_map<const MachineBasicBlock *, Range> BlockRanges;
+    std::unordered_map<MachineInstrStableID, Range> DestinationRanges;
+
+    friend class MachineMemoryDependenceAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "MachineMemoryDependence";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+[[nodiscard]] Expected<void> registerStage8MachineAnalyses(MachineAnalysisManager &Analyses);
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_MACHINEANALYSES_H
diff --git a/backend/include/rcc/CodeGen/MachineIRBuilder.h b/backend/include/rcc/CodeGen/MachineIRBuilder.h
index 2a5979b..2524c7a 100644
--- a/backend/include/rcc/CodeGen/MachineIRBuilder.h
+++ b/backend/include/rcc/CodeGen/MachineIRBuilder.h
@@ -161,6 +161,16 @@ public:
     return *Function;
   }
 
+  [[nodiscard]] const TargetDescription &target() const noexcept {
+    return *Target;
+  }
+
+  [[nodiscard]] MachineBasicBlock *insertionBlock() const noexcept {
+    return InsertBlock;
+  }
+
+  [[nodiscard]] Expected<void> verifyInsertPoint() const;
+
   [[nodiscard]] Expected<void> setInsertPoint(MachineBasicBlock &Block);
   [[nodiscard]] Expected<void> setInsertPointBefore(MachineInstr &Instruction);
   [[nodiscard]] Expected<void> setInsertPointAfter(MachineInstr &Instruction);
diff --git a/backend/include/rcc/CodeGen/MachineIRTypes.h b/backend/include/rcc/CodeGen/MachineIRTypes.h
index f7095cc..ea65eff 100644
--- a/backend/include/rcc/CodeGen/MachineIRTypes.h
+++ b/backend/include/rcc/CodeGen/MachineIRTypes.h
@@ -61,6 +61,7 @@ struct OriginIDTag;
 struct TargetConstantTypeIDTag;
 struct TargetFunctionStateTypeIDTag;
 struct TargetRelocationKindIDTag;
+struct CallingConventionIDTag;
 
 } // namespace detail
 
@@ -86,6 +87,7 @@ using OriginID = MachineIndex<detail::OriginIDTag, std::uint64_t>;
 using TargetConstantTypeID = MachineIndex<detail::TargetConstantTypeIDTag, std::uint64_t>;
 using TargetFunctionStateTypeID = MachineIndex<detail::TargetFunctionStateTypeIDTag, std::uint64_t>;
 using TargetRelocationKindID = MachineIndex<detail::TargetRelocationKindIDTag>;
+using CallingConventionID = MachineIndex<detail::CallingConventionIDTag>;
 
 class Alignment final {
 public:
@@ -298,6 +300,7 @@ struct SourceLocation final {
 static_assert(sizeof(Opcode) == sizeof(std::uint32_t));
 static_assert(sizeof(Alignment) == sizeof(std::uint64_t));
 static_assert(sizeof(FrameIndex) == sizeof(std::uint32_t));
+static_assert(sizeof(CallingConventionID) == sizeof(std::uint32_t));
 static_assert(sizeof(MemoryAliasSourceID) == sizeof(std::uint64_t));
 static_assert(std::is_trivially_copyable_v<Opcode>);
 static_assert(std::is_trivially_copyable_v<FrameIndex>);
diff --git a/backend/include/rcc/CodeGen/MachinePass.h b/backend/include/rcc/CodeGen/MachinePass.h
new file mode 100644
index 0000000..66e3b6b
--- /dev/null
+++ b/backend/include/rcc/CodeGen/MachinePass.h
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_MACHINEPASS_H
+#define RCC_CODEGEN_MACHINEPASS_H
+
+#include "rcc/CodeGen/InstructionDescriptor.h"
+#include "rcc/CodeGen/MachineFunctionProperties.h"
+#include "rcc/Support/Error.h"
+
+#include <concepts>
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <initializer_list>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <span>
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+namespace rcc {
+
+class CompilationUnit;
+class MachineFunction;
+class MachineVerifier;
+class TargetDescription;
+
+using AnalysisID = const void *;
+
+enum class MachinePassChange : std::uint32_t {
+  None = 0,
+  Instructions = 1U << 0U,
+  Operands = 1U << 1U,
+  Registers = 1U << 2U,
+  CFG = 1U << 3U,
+  BlockLayout = 1U << 4U,
+  Frame = 1U << 5U,
+  ConstantPool = 1U << 6U,
+  JumpTable = 1U << 7U,
+  TargetState = 1U << 8U,
+};
+
+class MachinePassChanges final {
+public:
+  constexpr MachinePassChanges() noexcept = default;
+  constexpr MachinePassChanges(std::initializer_list<MachinePassChange> Changes) noexcept {
+    for (const MachinePassChange Change : Changes)
+      add(Change);
+  }
+
+  [[nodiscard]] static constexpr MachinePassChanges all() noexcept {
+    return fromRaw((1U << 9U) - 1U);
+  }
+
+  [[nodiscard]] static constexpr MachinePassChanges fromRaw(std::uint32_t Bits) noexcept {
+    MachinePassChanges Result;
+    Result.Bits = Bits & rawMask();
+    return Result;
+  }
+
+  constexpr void add(MachinePassChange Change) noexcept {
+    Bits |= static_cast<std::uint32_t>(Change);
+  }
+
+  [[nodiscard]] constexpr bool has(MachinePassChange Change) const noexcept {
+    return (Bits & static_cast<std::uint32_t>(Change)) != 0;
+  }
+
+  [[nodiscard]] constexpr bool contains(MachinePassChanges Other) const noexcept {
+    return (Bits & Other.Bits) == Other.Bits;
+  }
+
+  [[nodiscard]] constexpr bool intersects(MachinePassChanges Other) const noexcept {
+    return (Bits & Other.Bits) != 0;
+  }
+
+  [[nodiscard]] constexpr bool empty() const noexcept {
+    return Bits == 0;
+  }
+
+  [[nodiscard]] constexpr std::uint32_t rawValue() const noexcept {
+    return Bits;
+  }
+
+  friend constexpr bool operator==(MachinePassChanges Left,
+                                   MachinePassChanges Right) noexcept = default;
+
+private:
+  [[nodiscard]] static constexpr std::uint32_t rawMask() noexcept {
+    return (1U << 9U) - 1U;
+  }
+
+  std::uint32_t Bits = 0;
+};
+
+class PreservedAnalyses final {
+public:
+  [[nodiscard]] static PreservedAnalyses all() noexcept {
+    PreservedAnalyses Result;
+    Result.PreserveAll = true;
+    return Result;
+  }
+
+  [[nodiscard]] static PreservedAnalyses none() noexcept {
+    return {};
+  }
+
+  void preserve(AnalysisID ID) {
+    if (ID != nullptr)
+      Preserved.insert(ID);
+  }
+
+  template <typename AnalysisT> void preserve() {
+    preserve(analysisID<AnalysisT>());
+  }
+
+  [[nodiscard]] bool preserves(AnalysisID ID) const noexcept {
+    return PreserveAll || (ID != nullptr && Preserved.contains(ID));
+  }
+
+  [[nodiscard]] bool preservesAll() const noexcept {
+    return PreserveAll;
+  }
+
+  template <typename AnalysisT> [[nodiscard]] static AnalysisID analysisID() noexcept {
+    static const std::uint8_t Token = 0;
+    return &Token;
+  }
+
+private:
+  bool PreserveAll = false;
+  std::unordered_set<AnalysisID> Preserved;
+};
+
+enum class PassThreadSafety : std::uint8_t {
+  NotThreadSafe,
+  ThreadSafe,
+};
+
+struct PassParameter final {
+  std::string Name;
+  std::string Description;
+  std::optional<std::string> DefaultValue;
+  bool Required = false;
+};
+
+struct MachinePassRegistrationMetadata {
+  std::vector<PassParameter> Parameters;
+  PassThreadSafety ThreadSafety = PassThreadSafety::NotThreadSafe;
+  MachinePassChanges DeclaredChanges = MachinePassChanges::all();
+};
+
+struct MachinePassContract final : MachinePassRegistrationMetadata {
+  std::string Name;
+  MachineFunctionProperties Requires;
+  MachineFunctionProperties Sets;
+  MachineFunctionProperties Clears;
+  std::vector<AnalysisID> RequiredAnalyses;
+  std::optional<PipelineStage> VerificationStage;
+};
+
+struct MachinePassResult final {
+  bool Changed = false;
+  MachinePassChanges Changes;
+  PreservedAnalyses Preserved = PreservedAnalyses::none();
+};
+
+struct CompilationUnitPassContract final {
+  std::string Name;
+  std::vector<AnalysisID> RequiredAnalyses;
+  std::vector<PassParameter> Parameters;
+  MachinePassChanges DeclaredChanges = MachinePassChanges::all();
+};
+
+struct CompilationUnitPassResult final {
+  bool Changed = false;
+  MachinePassChanges Changes;
+  PreservedAnalyses PreservedUnitAnalyses = PreservedAnalyses::none();
+  PreservedAnalyses PreservedFunctionAnalyses = PreservedAnalyses::none();
+};
+
+struct MachineAnalysisRegistration final {
+  AnalysisID ID = nullptr;
+  std::string Name;
+  std::vector<AnalysisID> Dependencies;
+  MachinePassChanges InvalidatedBy = MachinePassChanges::all();
+  PassThreadSafety ThreadSafety = PassThreadSafety::NotThreadSafe;
+};
+
+struct CompilationUnitAnalysisRegistration final {
+  AnalysisID ID = nullptr;
+  std::string Name;
+  std::vector<AnalysisID> Dependencies;
+  MachinePassChanges InvalidatedBy = MachinePassChanges::all();
+};
+
+class MachinePassInstrumentation;
+
+class MachineAnalysisManager final {
+public:
+  MachineAnalysisManager() = default;
+  MachineAnalysisManager(const MachineAnalysisManager &) = delete;
+  MachineAnalysisManager &operator=(const MachineAnalysisManager &) = delete;
+  MachineAnalysisManager(MachineAnalysisManager &&) = delete;
+  MachineAnalysisManager &operator=(MachineAnalysisManager &&) = delete;
+  ~MachineAnalysisManager() = default;
+
+  template <typename AnalysisT> [[nodiscard]] static AnalysisID id() noexcept {
+    return PreservedAnalyses::analysisID<AnalysisT>();
+  }
+
+  template <typename AnalysisT>
+  [[nodiscard]] Expected<void> registerAnalysis(MachineAnalysisRegistration Registration = {}) {
+    using ResultT = typename AnalysisT::Result;
+    if (Registration.ID == nullptr)
+      Registration.ID = id<AnalysisT>();
+    if (Registration.Name.empty()) {
+      if constexpr (requires {
+                      { AnalysisT::name() } -> std::convertible_to<std::string_view>;
+                    }) {
+        Registration.Name = std::string(AnalysisT::name());
+      } else {
+        Registration.Name = "unnamed-machine-analysis";
+      }
+    }
+
+    ErasedRunner Runner = [](MachineFunction &Function, const TargetDescription &Target,
+                             MachineAnalysisManager &Manager) -> Expected<std::shared_ptr<void>> {
+      auto Computed = AnalysisT::run(Function, Target, Manager);
+      if (!Computed)
+        return std::unexpected(Computed.error());
+      return std::shared_ptr<void>(new ResultT(std::move(*Computed)),
+                                   [](void *Value) { delete static_cast<ResultT *>(Value); });
+    };
+    ErasedInvalidator Invalidator = [](void *Value, const MachineFunction &Function,
+                                       const PreservedAnalyses &Preserved) -> bool {
+      if constexpr (requires(ResultT &Result, const MachineFunction &InputFunction,
+                             const PreservedAnalyses &Analyses) {
+                      { Result.invalidate(InputFunction, Analyses) } -> std::convertible_to<bool>;
+                    }) {
+        return static_cast<ResultT *>(Value)->invalidate(Function, Preserved);
+      }
+      return true;
+    };
+    return registerAnalysisImpl(std::move(Registration), std::move(Runner), std::move(Invalidator));
+  }
+
+  template <typename AnalysisT>
+  [[nodiscard]] Expected<typename AnalysisT::Result *> getResult(MachineFunction &Function,
+                                                                 const TargetDescription &Target) {
+    const AnalysisID Key = id<AnalysisT>();
+    if (!isRegistered(Key)) {
+      auto Registered = registerAnalysis<AnalysisT>();
+      if (!Registered)
+        return std::unexpected(Registered.error());
+    }
+    auto Result = getResultImpl(Key, Function, Target);
+    if (!Result)
+      return std::unexpected(Result.error());
+    return static_cast<typename AnalysisT::Result *>(*Result);
+  }
+
+  void invalidate(MachineFunction &Function, const PreservedAnalyses &Preserved,
+                  MachinePassChanges Changes) noexcept;
+  void invalidate(MachineFunction &Function, const PreservedAnalyses &Preserved) noexcept {
+    invalidate(Function, Preserved, MachinePassChanges::all());
+  }
+  [[nodiscard]] bool hasCached(const MachineFunction &Function, AnalysisID ID) const noexcept;
+  [[nodiscard]] bool isRegistered(AnalysisID ID) const noexcept;
+  [[nodiscard]] std::size_t cachedResultCount(const MachineFunction &Function) const noexcept;
+  void clear(MachineFunction &Function) noexcept;
+  void clearAll() noexcept;
+
+  [[nodiscard]] Expected<std::unique_ptr<MachineAnalysisManager>> forkEmpty() const;
+  [[nodiscard]] Expected<bool>
+  requestAction(std::string_view Action, const MachineFunction &Function, std::uint64_t Cost = 1);
+
+private:
+  using ErasedRunner = std::function<Expected<std::shared_ptr<void>>(
+      MachineFunction &, const TargetDescription &, MachineAnalysisManager &)>;
+  using ErasedInvalidator =
+      std::function<bool(void *, const MachineFunction &, const PreservedAnalyses &)>;
+
+  struct RegisteredAnalysis final {
+    MachineAnalysisRegistration Info;
+    ErasedRunner Runner;
+    ErasedInvalidator Invalidator;
+  };
+
+  struct CacheEntry final {
+    std::shared_ptr<void> Value;
+    AnalysisID ID = nullptr;
+  };
+
+  [[nodiscard]] Expected<void> registerAnalysisImpl(MachineAnalysisRegistration Registration,
+                                                    ErasedRunner Runner,
+                                                    ErasedInvalidator Invalidator);
+  [[nodiscard]] Expected<void *> getResultImpl(AnalysisID ID, MachineFunction &Function,
+                                               const TargetDescription &Target);
+  [[nodiscard]] Expected<void> materializeDependencies(const RegisteredAnalysis &Registration,
+                                                       MachineFunction &Function,
+                                                       const TargetDescription &Target);
+  [[nodiscard]] Expected<void>
+  validateParallelRequirements(std::span<const AnalysisID> RequiredAnalyses) const;
+  void setInstrumentation(MachinePassInstrumentation *NewInstrumentation) noexcept {
+    Instrumentation = NewInstrumentation;
+  }
+
+  std::unordered_map<AnalysisID, RegisteredAnalysis> Registry;
+  std::unordered_map<MachineFunction *, std::unordered_map<AnalysisID, CacheEntry>> Cache;
+  std::unordered_map<MachineFunction *, std::vector<AnalysisID>> ActiveComputations;
+  MachinePassInstrumentation *Instrumentation = nullptr;
+
+  friend class MachinePassManager;
+  friend class CompilationUnitPassManager;
+  friend Expected<void> registerStage8MachineAnalyses(MachineAnalysisManager &Analyses);
+};
+
+class CompilationUnitAnalysisManager final {
+public:
+  CompilationUnitAnalysisManager() = default;
+  CompilationUnitAnalysisManager(const CompilationUnitAnalysisManager &) = delete;
+  CompilationUnitAnalysisManager &operator=(const CompilationUnitAnalysisManager &) = delete;
+  CompilationUnitAnalysisManager(CompilationUnitAnalysisManager &&) = delete;
+  CompilationUnitAnalysisManager &operator=(CompilationUnitAnalysisManager &&) = delete;
+  ~CompilationUnitAnalysisManager() = default;
+
+  template <typename AnalysisT> [[nodiscard]] static AnalysisID id() noexcept {
+    return PreservedAnalyses::analysisID<AnalysisT>();
+  }
+
+  template <typename AnalysisT>
+  [[nodiscard]] Expected<void>
+  registerAnalysis(CompilationUnitAnalysisRegistration Registration = {}) {
+    using ResultT = typename AnalysisT::Result;
+    if (Registration.ID == nullptr)
+      Registration.ID = id<AnalysisT>();
+    if (Registration.Name.empty()) {
+      if constexpr (requires {
+                      { AnalysisT::name() } -> std::convertible_to<std::string_view>;
+                    }) {
+        Registration.Name = std::string(AnalysisT::name());
+      } else {
+        Registration.Name = "unnamed-compilation-unit-analysis";
+      }
+    }
+
+    ErasedRunner Runner =
+        [](CompilationUnit &Unit, const TargetDescription &Target,
+           CompilationUnitAnalysisManager &Manager) -> Expected<std::shared_ptr<void>> {
+      auto Computed = AnalysisT::run(Unit, Target, Manager);
+      if (!Computed)
+        return std::unexpected(Computed.error());
+      return std::shared_ptr<void>(new ResultT(std::move(*Computed)),
+                                   [](void *Value) { delete static_cast<ResultT *>(Value); });
+    };
+    ErasedInvalidator Invalidator = [](void *Value, const CompilationUnit &Unit,
+                                       const PreservedAnalyses &Preserved) -> bool {
+      if constexpr (requires(ResultT &Result, const CompilationUnit &InputUnit,
+                             const PreservedAnalyses &Analyses) {
+                      { Result.invalidate(InputUnit, Analyses) } -> std::convertible_to<bool>;
+                    }) {
+        return static_cast<ResultT *>(Value)->invalidate(Unit, Preserved);
+      }
+      return true;
+    };
+    return registerAnalysisImpl(std::move(Registration), std::move(Runner), std::move(Invalidator));
+  }
+
+  template <typename AnalysisT>
+  [[nodiscard]] Expected<typename AnalysisT::Result *> getResult(CompilationUnit &Unit,
+                                                                 const TargetDescription &Target) {
+    const AnalysisID Key = id<AnalysisT>();
+    if (!isRegistered(Key)) {
+      auto Registered = registerAnalysis<AnalysisT>();
+      if (!Registered)
+        return std::unexpected(Registered.error());
+    }
+    auto Result = getResultImpl(Key, Unit, Target);
+    if (!Result)
+      return std::unexpected(Result.error());
+    return static_cast<typename AnalysisT::Result *>(*Result);
+  }
+
+  void invalidate(CompilationUnit &Unit, const PreservedAnalyses &Preserved,
+                  MachinePassChanges Changes) noexcept;
+  [[nodiscard]] bool hasCached(const CompilationUnit &Unit, AnalysisID ID) const noexcept;
+  [[nodiscard]] bool isRegistered(AnalysisID ID) const noexcept;
+  void clear(CompilationUnit &Unit) noexcept;
+  void clearAll() noexcept;
+
+private:
+  using ErasedRunner = std::function<Expected<std::shared_ptr<void>>(
+      CompilationUnit &, const TargetDescription &, CompilationUnitAnalysisManager &)>;
+  using ErasedInvalidator =
+      std::function<bool(void *, const CompilationUnit &, const PreservedAnalyses &)>;
+
+  struct RegisteredAnalysis final {
+    CompilationUnitAnalysisRegistration Info;
+    ErasedRunner Runner;
+    ErasedInvalidator Invalidator;
+  };
+
+  struct CacheEntry final {
+    std::shared_ptr<void> Value;
+    AnalysisID ID = nullptr;
+  };
+
+  [[nodiscard]] Expected<void>
+  registerAnalysisImpl(CompilationUnitAnalysisRegistration Registration, ErasedRunner Runner,
+                       ErasedInvalidator Invalidator);
+  [[nodiscard]] Expected<void *> getResultImpl(AnalysisID ID, CompilationUnit &Unit,
+                                               const TargetDescription &Target);
+  [[nodiscard]] Expected<void> materializeDependencies(const RegisteredAnalysis &Registration,
+                                                       CompilationUnit &Unit,
+                                                       const TargetDescription &Target);
+  void setInstrumentation(MachinePassInstrumentation *NewInstrumentation) noexcept {
+    Instrumentation = NewInstrumentation;
+  }
+
+  std::unordered_map<AnalysisID, RegisteredAnalysis> Registry;
+  std::unordered_map<CompilationUnit *, std::unordered_map<AnalysisID, CacheEntry>> Cache;
+  std::unordered_map<CompilationUnit *, std::vector<AnalysisID>> ActiveComputations;
+  MachinePassInstrumentation *Instrumentation = nullptr;
+
+  friend class CompilationUnitPassManager;
+};
+
+class MachineFunctionPass {
+public:
+  MachineFunctionPass() = default;
+  MachineFunctionPass(const MachineFunctionPass &) = delete;
+  MachineFunctionPass &operator=(const MachineFunctionPass &) = delete;
+  virtual ~MachineFunctionPass() = default;
+
+  [[nodiscard]] virtual const MachinePassContract &contract() const noexcept = 0;
+  [[nodiscard]] virtual Expected<MachinePassResult> run(MachineFunction &Function,
+                                                        const TargetDescription &Target,
+                                                        MachineAnalysisManager &Analyses) = 0;
+};
+
+class CompilationUnitPass {
+public:
+  CompilationUnitPass() = default;
+  CompilationUnitPass(const CompilationUnitPass &) = delete;
+  CompilationUnitPass &operator=(const CompilationUnitPass &) = delete;
+  virtual ~CompilationUnitPass() = default;
+
+  [[nodiscard]] virtual const CompilationUnitPassContract &contract() const noexcept = 0;
+  [[nodiscard]] virtual Expected<CompilationUnitPassResult>
+  run(CompilationUnit &Unit, const TargetDescription &Target,
+      CompilationUnitAnalysisManager &UnitAnalyses, MachineAnalysisManager &FunctionAnalyses) = 0;
+};
+
+enum class InstrumentationPhase : std::uint8_t {
+  Before,
+  After,
+};
+
+struct InstrumentationStatistic final {
+  std::string Name;
+  bool IsAnalysis = false;
+  std::uint64_t Invocations = 0;
+  std::uint64_t CacheHits = 0;
+  std::uint64_t Changes = 0;
+  std::uint64_t Failures = 0;
+  std::uint64_t TotalNanoseconds = 0;
+};
+
+class MachinePassInstrumentation final {
+public:
+  using BeforeCallback = std::function<void(std::string_view, const MachineFunction &)>;
+  using AfterCallback =
+      std::function<void(std::string_view, const MachineFunction &, const MachinePassResult &)>;
+  using FailureCallback =
+      std::function<void(std::string_view, const MachineFunction &, const Error &)>;
+  using BeforeAnalysisCallback = std::function<void(std::string_view, const MachineFunction &)>;
+  using AfterAnalysisCallback =
+      std::function<void(std::string_view, const MachineFunction &, bool, std::uint64_t)>;
+  using AnalysisFailureCallback =
+      std::function<void(std::string_view, const MachineFunction &, const Error &)>;
+  using IRPrintCallback =
+      std::function<void(InstrumentationPhase, std::string_view, const MachineFunction &)>;
+  using ChangeCallback =
+      std::function<void(std::string_view, const MachineFunction &, MachinePassChanges, bool)>;
+  using ActionFilter =
+      std::function<bool(std::string_view, const MachineFunction &, std::uint64_t)>;
+
+  using BeforeUnitCallback = std::function<void(std::string_view, const CompilationUnit &)>;
+  using AfterUnitCallback = std::function<void(std::string_view, const CompilationUnit &,
+                                               const CompilationUnitPassResult &)>;
+  using UnitFailureCallback =
+      std::function<void(std::string_view, const CompilationUnit &, const Error &)>;
+  using BeforeUnitAnalysisCallback = std::function<void(std::string_view, const CompilationUnit &)>;
+  using AfterUnitAnalysisCallback =
+      std::function<void(std::string_view, const CompilationUnit &, bool, std::uint64_t)>;
+  using UnitAnalysisFailureCallback =
+      std::function<void(std::string_view, const CompilationUnit &, const Error &)>;
+
+  void addBeforeCallback(BeforeCallback Callback);
+  void addAfterCallback(AfterCallback Callback);
+  void addFailureCallback(FailureCallback Callback);
+  void addBeforeAnalysisCallback(BeforeAnalysisCallback Callback);
+  void addAfterAnalysisCallback(AfterAnalysisCallback Callback);
+  void addAnalysisFailureCallback(AnalysisFailureCallback Callback);
+  void addIRPrintCallback(IRPrintCallback Callback);
+  void addChangeCallback(ChangeCallback Callback);
+  void setActionFilter(ActionFilter Filter);
+  void setPerFunctionFuel(std::optional<std::uint64_t> Fuel);
+
+  void addBeforeUnitCallback(BeforeUnitCallback Callback);
+  void addAfterUnitCallback(AfterUnitCallback Callback);
+  void addUnitFailureCallback(UnitFailureCallback Callback);
+  void addBeforeUnitAnalysisCallback(BeforeUnitAnalysisCallback Callback);
+  void addAfterUnitAnalysisCallback(AfterUnitAnalysisCallback Callback);
+  void addUnitAnalysisFailureCallback(UnitAnalysisFailureCallback Callback);
+
+  [[nodiscard]] std::vector<InstrumentationStatistic> statistics() const;
+  void clearStatistics();
+
+private:
+  struct BufferedEvents final {
+    const TargetDescription *Target = nullptr;
+    std::vector<std::function<void()>> Events;
+  };
+
+  [[nodiscard]] bool bufferFunctionEvent(const MachineFunction &Function,
+                                         std::function<void(const MachineFunction &)> Replay) const;
+  void beginBuffering(BufferedEvents &Buffer, const TargetDescription &Target) const noexcept;
+  void endBuffering() const noexcept;
+  void replayBufferedEvents(BufferedEvents &Buffer) const;
+
+  void before(std::string_view Name, const MachineFunction &Function) const;
+  void after(std::string_view Name, const MachineFunction &Function,
+             const MachinePassResult &Result, std::uint64_t Nanoseconds) const;
+  void failure(std::string_view Name, const MachineFunction &Function, const Error &ErrorValue,
+               std::uint64_t Nanoseconds = 0) const;
+  void beforeAnalysis(std::string_view Name, const MachineFunction &Function) const;
+  void afterAnalysis(std::string_view Name, const MachineFunction &Function, bool CacheHit,
+                     std::uint64_t Nanoseconds) const;
+  void analysisFailure(std::string_view Name, const MachineFunction &Function,
+                       const Error &ErrorValue, std::uint64_t Nanoseconds) const;
+  void change(std::string_view Name, const MachineFunction &Function, MachinePassChanges Changes,
+              bool FingerprintChanged) const;
+  [[nodiscard]] Expected<bool> requestAction(std::string_view Action,
+                                             const MachineFunction &Function, std::uint64_t Cost);
+
+  void beforeUnit(std::string_view Name, const CompilationUnit &Unit) const;
+  void afterUnit(std::string_view Name, const CompilationUnit &Unit,
+                 const CompilationUnitPassResult &Result, std::uint64_t Nanoseconds) const;
+  void unitFailure(std::string_view Name, const CompilationUnit &Unit, const Error &ErrorValue,
+                   std::uint64_t Nanoseconds = 0) const;
+  void beforeUnitAnalysis(std::string_view Name, const CompilationUnit &Unit) const;
+  void afterUnitAnalysis(std::string_view Name, const CompilationUnit &Unit, bool CacheHit,
+                         std::uint64_t Nanoseconds) const;
+  void unitAnalysisFailure(std::string_view Name, const CompilationUnit &Unit,
+                           const Error &ErrorValue, std::uint64_t Nanoseconds) const;
+
+  [[nodiscard]] InstrumentationStatistic &statistic(std::string_view Name, bool IsAnalysis) const;
+
+  mutable std::mutex Mutex;
+  mutable std::mutex ActionMutex;
+  std::vector<BeforeCallback> Before;
+  std::vector<AfterCallback> After;
+  std::vector<FailureCallback> Failure;
+  std::vector<BeforeAnalysisCallback> BeforeAnalysis;
+  std::vector<AfterAnalysisCallback> AfterAnalysis;
+  std::vector<AnalysisFailureCallback> AnalysisFailure;
+  std::vector<IRPrintCallback> IRPrint;
+  std::vector<ChangeCallback> Change;
+  ActionFilter Filter;
+  std::optional<std::uint64_t> PerFunctionFuel;
+  std::unordered_map<std::uint64_t, std::uint64_t> ConsumedFuel;
+
+  std::vector<BeforeUnitCallback> BeforeUnit;
+  std::vector<AfterUnitCallback> AfterUnit;
+  std::vector<UnitFailureCallback> UnitFailure;
+  std::vector<BeforeUnitAnalysisCallback> BeforeUnitAnalysis;
+  std::vector<AfterUnitAnalysisCallback> AfterUnitAnalysis;
+  std::vector<UnitAnalysisFailureCallback> UnitAnalysisFailure;
+  mutable std::unordered_map<std::string, InstrumentationStatistic> Statistics;
+
+  static thread_local BufferedEvents *ActiveBuffer;
+
+  friend class CompilationUnitAnalysisManager;
+  friend class CompilationUnitPassManager;
+  friend class MachineAnalysisManager;
+  friend class MachinePassManager;
+};
+
+struct MachinePassManagerOptions final {
+  bool VerifyBefore = true;
+  bool VerifyEach = true;
+  bool DetectUnreportedChanges = false;
+};
+
+class MachinePassManager final {
+public:
+  explicit MachinePassManager(MachinePassManagerOptions Options = {}) : Options(Options) {}
+
+  MachinePassManager(const MachinePassManager &) = delete;
+  MachinePassManager &operator=(const MachinePassManager &) = delete;
+
+  [[nodiscard]] Expected<void> addPass(std::unique_ptr<MachineFunctionPass> Pass);
+  [[nodiscard]] Expected<void> run(MachineFunction &Function, const TargetDescription &Target,
+                                   MachineAnalysisManager &Analyses,
+                                   MachinePassInstrumentation *Instrumentation = nullptr) const;
+  [[nodiscard]] Expected<void>
+  runFunctions(CompilationUnit &Unit, const TargetDescription &Target,
+               const MachineAnalysisManager &AnalysisPrototype, std::size_t ThreadCount,
+               MachinePassInstrumentation *Instrumentation = nullptr) const;
+
+  [[nodiscard]] std::size_t size() const noexcept {
+    return Passes.size();
+  }
+
+private:
+  [[nodiscard]] Expected<void> validateContract(const MachinePassContract &Contract) const;
+
+  MachinePassManagerOptions Options;
+  std::vector<std::unique_ptr<MachineFunctionPass>> Passes;
+};
+
+struct CompilationUnitPassManagerOptions final {
+  bool VerifyBefore = true;
+  bool VerifyEach = true;
+};
+
+class CompilationUnitPassManager final {
+public:
+  explicit CompilationUnitPassManager(CompilationUnitPassManagerOptions Options = {})
+      : Options(Options) {}
+
+  CompilationUnitPassManager(const CompilationUnitPassManager &) = delete;
+  CompilationUnitPassManager &operator=(const CompilationUnitPassManager &) = delete;
+
+  [[nodiscard]] Expected<void> addPass(std::unique_ptr<CompilationUnitPass> Pass);
+  [[nodiscard]] Expected<void> run(CompilationUnit &Unit, const TargetDescription &Target,
+                                   CompilationUnitAnalysisManager &UnitAnalyses,
+                                   MachineAnalysisManager &FunctionAnalyses,
+                                   MachinePassInstrumentation *Instrumentation = nullptr) const;
+
+private:
+  CompilationUnitPassManagerOptions Options;
+  std::vector<std::unique_ptr<CompilationUnitPass>> Passes;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_MACHINEPASS_H
diff --git a/backend/include/rcc/CodeGen/TargetCallLowering.h b/backend/include/rcc/CodeGen/TargetCallLowering.h
new file mode 100644
index 0000000..a6b3535
--- /dev/null
+++ b/backend/include/rcc/CodeGen/TargetCallLowering.h
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_TARGETCALLLOWERING_H
+#define RCC_CODEGEN_TARGETCALLLOWERING_H
+
+#include "rcc/CodeGen/LowLevelType.h"
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/CodeGen/Register.h"
+#include "rcc/CodeGen/RegisterMask.h"
+#include "rcc/Support/Error.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <initializer_list>
+#include <memory>
+#include <optional>
+#include <span>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <variant>
+#include <vector>
+
+namespace rcc {
+
+class MachineIRBuilder;
+
+enum class ABIExtensionKind : std::uint8_t {
+  None,
+  AnyExtend,
+  SignExtend,
+  ZeroExtend,
+  Count,
+};
+
+enum class ABIValueFlag : std::uint8_t {
+  ByVal,
+  StructReturn,
+  Indirect,
+  InRegister,
+  Count,
+};
+
+class ABIValueFlags final {
+public:
+  constexpr ABIValueFlags() noexcept = default;
+
+  ABIValueFlags(std::initializer_list<ABIValueFlag> Flags) noexcept;
+
+  [[nodiscard]] constexpr bool has(ABIValueFlag Flag) const noexcept {
+    const auto Index = static_cast<std::uint32_t>(Flag);
+    return Index < static_cast<std::uint32_t>(ABIValueFlag::Count) &&
+           (Bits & (std::uint8_t{1} << Index)) != 0;
+  }
+
+  constexpr void set(ABIValueFlag Flag) noexcept {
+    const auto Index = static_cast<std::uint32_t>(Flag);
+    if (Index < static_cast<std::uint32_t>(ABIValueFlag::Count))
+      Bits |= std::uint8_t{1} << Index;
+  }
+
+  [[nodiscard]] constexpr std::uint8_t rawValue() const noexcept {
+    return Bits;
+  }
+
+  friend constexpr bool operator==(ABIValueFlags Left, ABIValueFlags Right) noexcept = default;
+
+private:
+  std::uint8_t Bits = 0;
+};
+
+struct ABIValue final {
+  Register Value;
+  LLT Type;
+  std::uint32_t OriginalValue = 0;
+  std::uint16_t FragmentIndex = 0;
+  std::uint16_t FragmentCount = 1;
+  std::uint32_t FragmentOffsetBytes = 0;
+  Alignment OriginalAlignment;
+  ABIExtensionKind Extension = ABIExtensionKind::None;
+  ABIValueFlags Flags;
+  std::uint64_t ByValSizeBytes = 0;
+  Alignment ByValAlignment;
+
+  friend bool operator==(const ABIValue &Left, const ABIValue &Right) = default;
+};
+
+enum class MachineCallTargetKind : std::uint8_t {
+  Invalid,
+  GlobalSymbol,
+  ExternalSymbol,
+  IndirectRegister,
+};
+
+class MachineCallTarget final {
+public:
+  constexpr MachineCallTarget() noexcept = default;
+
+  [[nodiscard]] static Expected<MachineCallTarget> globalSymbol(std::string Name,
+                                                                std::uint32_t TargetFlags = 0);
+  [[nodiscard]] static Expected<MachineCallTarget> externalSymbol(std::string Name,
+                                                                  std::uint32_t TargetFlags = 0);
+  [[nodiscard]] static Expected<MachineCallTarget> indirect(Register Callee,
+                                                            std::uint32_t TargetFlags = 0);
+
+  [[nodiscard]] MachineCallTargetKind kind() const noexcept {
+    return Kind;
+  }
+
+  [[nodiscard]] std::string_view symbolName() const noexcept;
+  [[nodiscard]] Register indirectRegister() const noexcept;
+  [[nodiscard]] std::uint32_t targetFlags() const noexcept {
+    return TargetFlags;
+  }
+
+  [[nodiscard]] bool isValid() const noexcept {
+    return Kind != MachineCallTargetKind::Invalid;
+  }
+
+  friend bool operator==(const MachineCallTarget &Left, const MachineCallTarget &Right) = default;
+
+private:
+  using Storage = std::variant<std::monostate, std::string, Register>;
+
+  MachineCallTarget(MachineCallTargetKind Kind, Storage Value, std::uint32_t TargetFlags) noexcept
+      : Kind(Kind), Value(std::move(Value)), TargetFlags(TargetFlags) {}
+
+  MachineCallTargetKind Kind = MachineCallTargetKind::Invalid;
+  Storage Value;
+  std::uint32_t TargetFlags = 0;
+};
+
+enum class TailCallKind : std::uint8_t {
+  NotTail,
+  Tail,
+  MustTail,
+};
+
+struct TailCallContext final {
+  CallingConventionID CallerConvention;
+  std::vector<ABIValue> CallerReturns;
+  std::uint64_t ReusableIncomingArgumentBytes = 0;
+  std::size_t CallerFixedArgumentCount = 0;
+  bool CallerIsVariadic = false;
+  bool CallerHasDynamicStackAllocation = false;
+  bool CallerUsesStructReturn = false;
+};
+
+struct FormalArgumentRequest final {
+  CallingConventionID Convention;
+  std::vector<ABIValue> Arguments;
+  std::size_t FixedArgumentCount = 0;
+  bool IsVariadic = false;
+};
+
+struct CallLoweringRequest final {
+  CallingConventionID Convention;
+  MachineCallTarget Callee;
+  std::vector<ABIValue> Arguments;
+  std::vector<ABIValue> Results;
+  std::size_t FixedArgumentCount = 0;
+  std::uint64_t CallSiteID = 0;
+  bool IsVariadic = false;
+  TailCallKind TailKind = TailCallKind::NotTail;
+  std::optional<TailCallContext> TailContext;
+};
+
+struct ReturnLoweringRequest final {
+  CallingConventionID Convention;
+  std::vector<ABIValue> Values;
+  bool FunctionIsVariadic = false;
+};
+
+enum class CCLocationKind : std::uint8_t {
+  Register,
+  Stack,
+  Indirect,
+  Custom,
+};
+
+enum class CCAssignmentFlag : std::uint8_t {
+  Variadic,
+  ByVal,
+  StructReturn,
+  Indirect,
+  InRegister,
+  Bitcast,
+  Count,
+};
+
+class CCAssignmentFlags final {
+public:
+  constexpr CCAssignmentFlags() noexcept = default;
+
+  CCAssignmentFlags(std::initializer_list<CCAssignmentFlag> Flags) noexcept;
+
+  [[nodiscard]] constexpr bool has(CCAssignmentFlag Flag) const noexcept {
+    const auto Index = static_cast<std::uint32_t>(Flag);
+    return Index < static_cast<std::uint32_t>(CCAssignmentFlag::Count) &&
+           (Bits & (std::uint8_t{1} << Index)) != 0;
+  }
+
+  constexpr void set(CCAssignmentFlag Flag) noexcept {
+    const auto Index = static_cast<std::uint32_t>(Flag);
+    if (Index < static_cast<std::uint32_t>(CCAssignmentFlag::Count))
+      Bits |= std::uint8_t{1} << Index;
+  }
+
+  [[nodiscard]] constexpr std::uint8_t rawValue() const noexcept {
+    return Bits;
+  }
+
+  friend constexpr bool operator==(CCAssignmentFlags Left,
+                                   CCAssignmentFlags Right) noexcept = default;
+
+private:
+  std::uint8_t Bits = 0;
+};
+
+struct CCAssignment final {
+  std::size_t ValueIndex = 0;
+  Register OriginalValue;
+  std::uint32_t OriginalValueIndex = 0;
+  std::uint16_t FragmentIndex = 0;
+  std::uint16_t FragmentCount = 1;
+  LLT ValueType;
+  LLT LocationType;
+  CCLocationKind LocationKind = CCLocationKind::Register;
+  std::optional<PhysicalRegister> LocationRegister;
+  std::optional<std::uint64_t> StackOffsetBytes;
+  std::uint64_t LocationSizeBytes = 0;
+  std::uint64_t StackSlotSizeBytes = 0;
+  Alignment LocationAlignment;
+  ABIExtensionKind Extension = ABIExtensionKind::None;
+  CCAssignmentFlags CustomFlags;
+
+  friend bool operator==(const CCAssignment &Left, const CCAssignment &Right) = default;
+};
+
+struct StackArgumentArea final {
+  std::uint64_t SizeBytes = 0;
+  std::uint64_t ShadowSpaceBytes = 0;
+  Alignment Align;
+
+  friend bool operator==(StackArgumentArea Left, StackArgumentArea Right) noexcept = default;
+};
+
+struct CallFrameRequirements final {
+  std::uint64_t SizeBytes = 0;
+  Alignment Align;
+  bool EmitSetup = false;
+  bool EmitDestroy = false;
+  bool ReusesIncomingArea = false;
+
+  friend bool operator==(CallFrameRequirements Left,
+                         CallFrameRequirements Right) noexcept = default;
+};
+
+struct VarArgRegisterSave final {
+  PhysicalRegister Reg;
+  std::uint64_t OffsetBytes = 0;
+
+  friend bool operator==(VarArgRegisterSave Left, VarArgRegisterSave Right) noexcept = default;
+};
+
+struct VarArgLoweringState final {
+  bool IsVariadic = false;
+  std::size_t FixedArgumentCount = 0;
+  std::size_t FirstUnallocatedIntegerRegister = 0;
+  std::uint64_t OverflowAreaOffsetBytes = 0;
+  std::int64_t RegisterSaveAreaOffsetBytes = 0;
+  std::uint64_t RegisterSaveAreaSizeBytes = 0;
+  std::uint64_t RegisterSavePaddingBytes = 0;
+  std::vector<VarArgRegisterSave> RegistersToSave;
+
+  friend bool operator==(const VarArgLoweringState &Left,
+                         const VarArgLoweringState &Right) = default;
+};
+
+struct ByValCopyAssignment final {
+  std::size_t ArgumentAssignmentIndex = 0;
+  Register Source;
+  LLT PointerType;
+  std::uint64_t StackOffsetBytes = 0;
+  std::uint64_t SizeBytes = 0;
+  Alignment Align;
+
+  friend bool operator==(ByValCopyAssignment Left, ByValCopyAssignment Right) noexcept = default;
+};
+
+enum class CallLoweringPlanKind : std::uint8_t {
+  FormalArguments,
+  Call,
+  Return,
+};
+
+struct CallLoweringPlanDesc final {
+  CallLoweringPlanKind Kind = CallLoweringPlanKind::FormalArguments;
+  std::string Target;
+  CallingConventionID Convention;
+  std::vector<CCAssignment> ArgumentAssignments;
+  std::vector<CCAssignment> ReturnAssignments;
+  StackArgumentArea StackArguments;
+  CallFrameRequirements CallFrame;
+  VarArgLoweringState VarArgs;
+  std::vector<ByValCopyAssignment> ByValCopies;
+  std::shared_ptr<const RegisterMask> PreservedMask;
+  std::optional<MachineCallTarget> Callee;
+  std::uint64_t CallSiteID = 0;
+  TailCallKind TailDecision = TailCallKind::NotTail;
+  std::string TailRejectionReason;
+};
+
+class CallLoweringPlan final {
+public:
+  [[nodiscard]] static Expected<CallLoweringPlan> create(CallLoweringPlanDesc Description);
+
+  [[nodiscard]] CallLoweringPlanKind kind() const noexcept {
+    return Description.Kind;
+  }
+
+  [[nodiscard]] std::string_view target() const noexcept {
+    return Description.Target;
+  }
+
+  [[nodiscard]] CallingConventionID convention() const noexcept {
+    return Description.Convention;
+  }
+
+  [[nodiscard]] std::span<const CCAssignment> argumentAssignments() const noexcept {
+    return Description.ArgumentAssignments;
+  }
+
+  [[nodiscard]] std::span<const CCAssignment> returnAssignments() const noexcept {
+    return Description.ReturnAssignments;
+  }
+
+  [[nodiscard]] const StackArgumentArea &stackArguments() const noexcept {
+    return Description.StackArguments;
+  }
+
+  [[nodiscard]] const CallFrameRequirements &callFrame() const noexcept {
+    return Description.CallFrame;
+  }
+
+  [[nodiscard]] const VarArgLoweringState &varArgs() const noexcept {
+    return Description.VarArgs;
+  }
+
+  [[nodiscard]] std::span<const ByValCopyAssignment> byValCopies() const noexcept {
+    return Description.ByValCopies;
+  }
+
+  [[nodiscard]] const std::shared_ptr<const RegisterMask> &preservedMask() const noexcept {
+    return Description.PreservedMask;
+  }
+
+  [[nodiscard]] const MachineCallTarget *callee() const noexcept {
+    return Description.Callee ? &*Description.Callee : nullptr;
+  }
+
+  [[nodiscard]] std::uint64_t callSiteID() const noexcept {
+    return Description.CallSiteID;
+  }
+
+  [[nodiscard]] TailCallKind tailDecision() const noexcept {
+    return Description.TailDecision;
+  }
+
+  [[nodiscard]] std::string_view tailRejectionReason() const noexcept {
+    return Description.TailRejectionReason;
+  }
+
+private:
+  explicit CallLoweringPlan(CallLoweringPlanDesc Description)
+      : Description(std::move(Description)) {}
+
+  CallLoweringPlanDesc Description;
+};
+
+class TargetCallLowering {
+public:
+  virtual ~TargetCallLowering() = default;
+
+  [[nodiscard]] Expected<void> lowerFormalArguments(MachineIRBuilder &Builder,
+                                                    const FormalArgumentRequest &Request) const;
+  [[nodiscard]] Expected<void> lowerCall(MachineIRBuilder &Builder,
+                                         const CallLoweringRequest &Request) const;
+  [[nodiscard]] Expected<void> lowerReturn(MachineIRBuilder &Builder,
+                                           const ReturnLoweringRequest &Request) const;
+
+  [[nodiscard]] virtual Expected<CallLoweringPlan>
+  planFormalArguments(const FormalArgumentRequest &Request) const = 0;
+  [[nodiscard]] virtual Expected<CallLoweringPlan>
+  planCall(const CallLoweringRequest &Request) const = 0;
+  [[nodiscard]] virtual Expected<CallLoweringPlan>
+  planReturn(const ReturnLoweringRequest &Request) const = 0;
+  [[nodiscard]] virtual Expected<void> emitPlan(MachineIRBuilder &Builder,
+                                                const CallLoweringPlan &Plan) const = 0;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_TARGETCALLLOWERING_H
diff --git a/backend/include/rcc/Target/RISCV/RISCVCallLowering.h b/backend/include/rcc/Target/RISCV/RISCVCallLowering.h
new file mode 100644
index 0000000..445c922
--- /dev/null
+++ b/backend/include/rcc/Target/RISCV/RISCVCallLowering.h
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_TARGET_RISCV_RISCVCALLLOWERING_H
+#define RCC_TARGET_RISCV_RISCVCALLLOWERING_H
+
+#include "rcc/CodeGen/TargetCallLowering.h"
+#include "rcc/Target/RISCV/RISCVInstructions.h"
+
+#include <cstdint>
+
+namespace rcc::riscv {
+
+enum class CallTargetFlag : std::uint32_t {
+  DirectCall = 1U << 0U,
+};
+
+enum class CallStackObjectFlag : std::uint64_t {
+  IncomingArgument = 1ULL << 0U,
+  OutgoingArgument = 1ULL << 1U,
+  ByValCopy = 1ULL << 2U,
+  VarArgSaveArea = 1ULL << 3U,
+  VarArgAlignmentPadding = 1ULL << 4U,
+};
+
+enum class CallValueTransform : std::uint8_t {
+  Full,
+  AnyExtend,
+  SignExtend,
+  ZeroExtend,
+  Truncate,
+  Bitcast,
+};
+
+[[nodiscard]] constexpr CallingConventionID
+callingConventionID(CallingConvention Convention) noexcept {
+  return CallingConventionID::fromValue(static_cast<std::uint32_t>(Convention));
+}
+
+[[nodiscard]] const TargetCallLowering &callLowering() noexcept;
+
+} // namespace rcc::riscv
+
+#endif // RCC_TARGET_RISCV_RISCVCALLLOWERING_H