[CIR][X86] Implement xsave/xrstor builtins Fixes part of #167752 (#170877)

Handle xsave/xrstor family of X86 builtins in ClangIR Part of #167752 --------- Signed-off-by: Medha Tiwari <medhatiwari@ibm.com>
2026-01-13 19:08:21 +08:00 · 2025-12-10 02:19:42 +05:30
parent 0895163097
commit 019a294771
2 changed files with 264 additions and 1 deletions
--- a/clang/lib/CIR/CodeGen/CIRGenBuiltinX86.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenBuiltinX86.cpp
@@ -544,9 +544,78 @@ mlir::Value CIRGenFunction::emitX86BuiltinExpr(unsigned builtinID,
  case X86::BI__builtin_ia32_xsaves:
  case X86::BI__builtin_ia32_xsaves64:
  case X86::BI__builtin_ia32_xsetbv:
-  case X86::BI_xsetbv:
+  case X86::BI_xsetbv: {
+    mlir::Location loc = getLoc(expr->getExprLoc());
+    StringRef intrinsicName;
+    switch (builtinID) {
+    default:
+      llvm_unreachable("Unexpected builtin");
+    case X86::BI__builtin_ia32_xsave:
+      intrinsicName = "x86.xsave";
+      break;
+    case X86::BI__builtin_ia32_xsave64:
+      intrinsicName = "x86.xsave64";
+      break;
+    case X86::BI__builtin_ia32_xrstor:
+      intrinsicName = "x86.xrstor";
+      break;
+    case X86::BI__builtin_ia32_xrstor64:
+      intrinsicName = "x86.xrstor64";
+      break;
+    case X86::BI__builtin_ia32_xsaveopt:
+      intrinsicName = "x86.xsaveopt";
+      break;
+    case X86::BI__builtin_ia32_xsaveopt64:
+      intrinsicName = "x86.xsaveopt64";
+      break;
+    case X86::BI__builtin_ia32_xrstors:
+      intrinsicName = "x86.xrstors";
+      break;
+    case X86::BI__builtin_ia32_xrstors64:
+      intrinsicName = "x86.xrstors64";
+      break;
+    case X86::BI__builtin_ia32_xsavec:
+      intrinsicName = "x86.xsavec";
+      break;
+    case X86::BI__builtin_ia32_xsavec64:
+      intrinsicName = "x86.xsavec64";
+      break;
+    case X86::BI__builtin_ia32_xsaves:
+      intrinsicName = "x86.xsaves";
+      break;
+    case X86::BI__builtin_ia32_xsaves64:
+      intrinsicName = "x86.xsaves64";
+      break;
+    case X86::BI__builtin_ia32_xsetbv:
+    case X86::BI_xsetbv:
+      intrinsicName = "x86.xsetbv";
+      break;
+    }
+
+    // The xsave family of instructions take a 64-bit mask that specifies
+    // which processor state components to save/restore. The hardware expects
+    // this mask split into two 32-bit registers: EDX (high 32 bits) and
+    // EAX (low 32 bits).
+    mlir::Type i32Ty = builder.getSInt32Ty();
+
+    // Mhi = (uint32_t)(ops[1] >> 32) - extract high 32 bits via right shift
+    cir::ConstantOp shift32 = builder.getSInt64(32, loc);
+    mlir::Value mhi = builder.createShift(loc, ops[1], shift32.getResult(),
+                                          /*isShiftLeft=*/false);
+    mhi = builder.createIntCast(mhi, i32Ty);
+
+    // Mlo = (uint32_t)ops[1] - extract low 32 bits by truncation
+    mlir::Value mlo = builder.createIntCast(ops[1], i32Ty);
+
+    return emitIntrinsicCallOp(builder, loc, intrinsicName, voidTy,
+                               mlir::ValueRange{ops[0], mhi, mlo});
+  }
  case X86::BI__builtin_ia32_xgetbv:
  case X86::BI_xgetbv:
+    // xgetbv reads the extended control register specified by ops[0] (ECX)
+    // and returns the 64-bit value
+    return emitIntrinsicCallOp(builder, getLoc(expr->getExprLoc()),
+                               "x86.xgetbv", builder.getUInt64Ty(), ops[0]);
  case X86::BI__builtin_ia32_storedqudi128_mask:
  case X86::BI__builtin_ia32_storedqusi128_mask:
  case X86::BI__builtin_ia32_storedquhi128_mask:
--- a/clang/test/CIR/CodeGenBuiltins/X86/xsave-builtins.c
+++ b/clang/test/CIR/CodeGenBuiltins/X86/xsave-builtins.c
@@ -0,0 +1,194 @@
+// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-linux -target-feature +xsave -target-feature +xsaveopt -target-feature +xsavec -target-feature +xsaves -fclangir -emit-cir -o %t.cir -Wall -Werror
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-linux -target-feature +xsave -target-feature +xsaveopt -target-feature +xsavec -target-feature +xsaves -fclangir -emit-llvm -o %t.ll -Wall -Werror
+// RUN: FileCheck --check-prefixes=LLVM --input-file=%t.ll %s
+
+// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-linux -target-feature +xsave -target-feature +xsaveopt -target-feature +xsavec -target-feature +xsaves -emit-llvm -o - -Wall -Werror | FileCheck %s -check-prefix=OGCG
+
+void test_xsave(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsave
+  // CIR: [[P:%.*]] = cir.load {{.*}} : !cir.ptr<!cir.ptr<!void>>, !cir.ptr<!void>
+  // CIR: [[M:%.*]] = cir.load {{.*}} : !cir.ptr<!u64i>, !u64i
+  // CIR: [[CONST:%.*]] = cir.const #cir.int<32> : !s64i
+  // CIR: [[SHIFT:%.*]] = cir.shift(right, [[M]] : !u64i, [[CONST]] : !s64i) -> !u64i
+  // CIR: [[CAST1:%.*]] = cir.cast integral [[SHIFT]] : !u64i -> !s32i
+  // CIR: [[CAST2:%.*]] = cir.cast integral [[M]] : !u64i -> !s32i
+  // CIR: cir.call_llvm_intrinsic "x86.xsave" [[P]], [[CAST1]], [[CAST2]]
+
+  // LLVM-LABEL: test_xsave
+  // LLVM: [[LP:%.*]] = load ptr, ptr
+  // LLVM: [[LM:%.*]] = load i64, ptr
+  // LLVM: [[LSHIFT:%.*]] = lshr i64 [[LM]], 32
+  // LLVM: [[LCAST1:%.*]] = trunc i64 [[LSHIFT]] to i32
+  // LLVM: [[LCAST2:%.*]] = trunc i64 [[LM]] to i32
+  // LLVM: call void @llvm.x86.xsave(ptr [[LP]], i32 [[LCAST1]], i32 [[LCAST2]])
+
+  // OGCG-LABEL: test_xsave
+  // OGCG: [[OP:%.*]] = load ptr, ptr
+  // OGCG: [[OM:%.*]] = load i64, ptr
+  // OGCG: [[OSHIFT:%.*]] = lshr i64 [[OM]], 32
+  // OGCG: [[OCAST1:%.*]] = trunc i64 [[OSHIFT]] to i32
+  // OGCG: [[OCAST2:%.*]] = trunc i64 [[OM]] to i32
+  // OGCG: call void @llvm.x86.xsave(ptr [[OP]], i32 [[OCAST1]], i32 [[OCAST2]])
+  __builtin_ia32_xsave(p, m);
+}
+
+// The following tests use the same pattern as test_xsave (load, shift, cast, cast, intrinsic call).
+// Only the intrinsic name differs, so we just check the intrinsic call.
+
+void test_xsave64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsave64
+  // CIR: cir.call_llvm_intrinsic "x86.xsave64"
+
+  // LLVM-LABEL: test_xsave64
+  // LLVM: call void @llvm.x86.xsave64
+
+  // OGCG-LABEL: test_xsave64
+  // OGCG: call void @llvm.x86.xsave64
+  __builtin_ia32_xsave64(p, m);
+}
+
+void test_xrstor(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xrstor
+  // CIR: cir.call_llvm_intrinsic "x86.xrstor"
+
+  // LLVM-LABEL: test_xrstor
+  // LLVM: call void @llvm.x86.xrstor
+
+  // OGCG-LABEL: test_xrstor
+  // OGCG: call void @llvm.x86.xrstor
+  __builtin_ia32_xrstor(p, m);
+}
+
+void test_xrstor64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xrstor64
+  // CIR: cir.call_llvm_intrinsic "x86.xrstor64"
+
+  // LLVM-LABEL: test_xrstor64
+  // LLVM: call void @llvm.x86.xrstor64
+
+  // OGCG-LABEL: test_xrstor64
+  // OGCG: call void @llvm.x86.xrstor64
+  __builtin_ia32_xrstor64(p, m);
+}
+
+void test_xsaveopt(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsaveopt
+  // CIR: cir.call_llvm_intrinsic "x86.xsaveopt"
+
+  // LLVM-LABEL: test_xsaveopt
+  // LLVM: call void @llvm.x86.xsaveopt
+
+  // OGCG-LABEL: test_xsaveopt
+  // OGCG: call void @llvm.x86.xsaveopt
+  __builtin_ia32_xsaveopt(p, m);
+}
+
+void test_xsaveopt64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsaveopt64
+  // CIR: cir.call_llvm_intrinsic "x86.xsaveopt64"
+
+  // LLVM-LABEL: test_xsaveopt64
+  // LLVM: call void @llvm.x86.xsaveopt64
+
+  // OGCG-LABEL: test_xsaveopt64
+  // OGCG: call void @llvm.x86.xsaveopt64
+  __builtin_ia32_xsaveopt64(p, m);
+}
+
+void test_xsavec(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsavec
+  // CIR: cir.call_llvm_intrinsic "x86.xsavec"
+
+  // LLVM-LABEL: test_xsavec
+  // LLVM: call void @llvm.x86.xsavec
+
+  // OGCG-LABEL: test_xsavec
+  // OGCG: call void @llvm.x86.xsavec
+  __builtin_ia32_xsavec(p, m);
+}
+
+void test_xsavec64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsavec64
+  // CIR: cir.call_llvm_intrinsic "x86.xsavec64"
+
+  // LLVM-LABEL: test_xsavec64
+  // LLVM: call void @llvm.x86.xsavec64
+
+  // OGCG-LABEL: test_xsavec64
+  // OGCG: call void @llvm.x86.xsavec64
+  __builtin_ia32_xsavec64(p, m);
+}
+
+void test_xsaves(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsaves
+  // CIR: cir.call_llvm_intrinsic "x86.xsaves"
+
+  // LLVM-LABEL: test_xsaves
+  // LLVM: call void @llvm.x86.xsaves
+
+  // OGCG-LABEL: test_xsaves
+  // OGCG: call void @llvm.x86.xsaves
+  __builtin_ia32_xsaves(p, m);
+}
+
+void test_xsaves64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xsaves64
+  // CIR: cir.call_llvm_intrinsic "x86.xsaves64"
+
+  // LLVM-LABEL: test_xsaves64
+  // LLVM: call void @llvm.x86.xsaves64
+
+  // OGCG-LABEL: test_xsaves64
+  // OGCG: call void @llvm.x86.xsaves64
+  __builtin_ia32_xsaves64(p, m);
+}
+
+void test_xrstors(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xrstors
+  // CIR: cir.call_llvm_intrinsic "x86.xrstors"
+
+  // LLVM-LABEL: test_xrstors
+  // LLVM: call void @llvm.x86.xrstors
+
+  // OGCG-LABEL: test_xrstors
+  // OGCG: call void @llvm.x86.xrstors
+  __builtin_ia32_xrstors(p, m);
+}
+
+void test_xrstors64(void *p, unsigned long long m) {
+  // CIR-LABEL: test_xrstors64
+  // CIR: cir.call_llvm_intrinsic "x86.xrstors64"
+
+  // LLVM-LABEL: test_xrstors64
+  // LLVM: call void @llvm.x86.xrstors64
+
+  // OGCG-LABEL: test_xrstors64
+  // OGCG: call void @llvm.x86.xrstors64
+  __builtin_ia32_xrstors64(p, m);
+}
+
+unsigned long long test_xgetbv(unsigned int a) {
+  // CIR-LABEL: test_xgetbv
+  // CIR: cir.call_llvm_intrinsic "x86.xgetbv"
+
+  // LLVM-LABEL: test_xgetbv
+  // LLVM: call i64 @llvm.x86.xgetbv
+
+  // OGCG-LABEL: test_xgetbv
+  // OGCG: call i64 @llvm.x86.xgetbv
+  return __builtin_ia32_xgetbv(a);
+}
+
+void test_xsetbv(unsigned int a, unsigned long long m) {
+  // CIR-LABEL: test_xsetbv
+  // CIR: cir.call_llvm_intrinsic "x86.xsetbv"
+
+  // LLVM-LABEL: test_xsetbv
+  // LLVM: call void @llvm.x86.xsetbv
+
+  // OGCG-LABEL: test_xsetbv
+  // OGCG: call void @llvm.x86.xsetbv
+  __builtin_ia32_xsetbv(a, m);
+}
+