[PATCH] D51805: [X86] Custom emit __builtin_rdtscp so we can emit an explicit store for the out parameter

[Craig Topper via Phabricator via cfe-commits]

craig.topper created this revision.
craig.topper added reviewers: RKSimon, spatel.

This is the clang side of https://reviews.llvm.org/D51803. The llvm intrinsic now returns two results. So we need to emit an explicit store in IR for the out parameter. This is similar to addcarry/subborrow/rdrand/rdseed.


https://reviews.llvm.org/D51805

Files:
  lib/CodeGen/CGBuiltin.cpp
  test/CodeGen/rd-builtins.c


Index: test/CodeGen/rd-builtins.c
===================================================================
--- test/CodeGen/rd-builtins.c
+++ test/CodeGen/rd-builtins.c
@@ -14,3 +14,12 @@
 // CHECK: @test_rdtsc
 // CHECK: call i64 @llvm.x86.rdtsc
 }
+
+unsigned long long test_rdtscp(unsigned int *a) {
+// CHECK: @test_rdtscp
+// CHECK: [[RDTSCP:%.*]] = call { i64, i32 } @llvm.x86.rdtscp
+// CHECK: [[TSC_AUX:%.*]] = extractvalue { i64, i32 } [[RDTSCP]], 1
+// CHECK: store i32 [[TSC_AUX]], i32* %{{.*}}
+// CHECK: [[TSC:%.*]] = extractvalue { i64, i32 } [[RDTSCP]], 0
+  return __rdtscp(a);
+}
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -9158,6 +9158,12 @@
   case X86::BI__rdtsc: {
     return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_rdtsc));
   }
+  case X86::BI__builtin_ia32_rdtscp: {
+    Value *Call = Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_rdtscp));
+    Builder.CreateDefaultAlignedStore(Builder.CreateExtractValue(Call, 1),
+                                      Ops[0]);
+    return Builder.CreateExtractValue(Call, 0);
+  }
   case X86::BI__builtin_ia32_undef128:
   case X86::BI__builtin_ia32_undef256:
   case X86::BI__builtin_ia32_undef512:


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