[X86] Add support for Read Time Stamp Counter x86 builtin intrinsics.

This patch:
- Adds two new X86 builtin intrinsics ('int_x86_rdtsc' and
   'int_x86_rdtscp') as GCCBuiltin intrinsics;
- Teaches the backend how to lower the two new builtins;
- Introduces a common function to lower READCYCLECOUNTER dag nodes
  and the two new rdtsc/rdtscp intrinsics;
- Improves (and extends) the existing x86 test 'rdtsc.ll'; now test 'rdtsc.ll'
  correctly verifies that both READCYCLECOUNTER and the two new intrinsics
  work fine for both 64bit and 32bit Subtargets.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207127 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 6 deletions

diff --git a/test/CodeGen/X86/rdtsc.ll b/test/CodeGen/X86/rdtsc.ll
index f21a44c360..f169742931 100644
--- a/test/CodeGen/X86/rdtsc.ll
+++ b/test/CodeGen/X86/rdtsc.ll
@@ -1,8 +1,49 @@
-; RUN: llc < %s -march=x86 | grep rdtsc
-; RUN: llc < %s -march=x86-64 | grep rdtsc
-declare i64 @llvm.readcyclecounter()
+; RUN: llc < %s -march=x86-64 -mcpu=generic | FileCheck %s
+; RUN: llc < %s -march=x86 -mcpu=generic | FileCheck %s --check-prefix=CHECK --check-prefix=X86
+
+; Verify that we correctly lower ISD::READCYCLECOUNTER.
+
+
+define i64 @test_builtin_readcyclecounter() {
+  %1 = tail call i64 @llvm.readcyclecounter()
+  ret i64 %1
+}
+; CHECK-LABEL: test_builtin_readcyclecounter
+; CHECK: rdtsc
+; X86-NOT: shlq
+; X86-NOT: or
+; CHECK-NOT: mov
+; CHECK: ret
+
+
+; Verify that we correctly lower the Read Cycle Counter GCC x86 builtins
+; (i.e. RDTSC and RDTSCP).
 
-define i64 @foo() {
-	%tmp.1 = call i64 @llvm.readcyclecounter( )		; <i64> [#uses=1]
-	ret i64 %tmp.1
+define i64 @test_builtin_rdtsc() {
+  %1 = tail call i64 @llvm.x86.rdtsc()
+  ret i64 %1
 }
+; CHECK-LABEL: test_builtin_rdtsc
+; CHECK: rdtsc
+; X86-NOT: shlq
+; X86-NOT: or
+; CHECK-NOT: mov
+; CHECK: ret
+
+
+define i64 @test_builtin_rdtscp(i8* %A) {
+  %1 = tail call i64 @llvm.x86.rdtscp(i8* %A)
+  ret i64 %1
+}
+; CHECK-LABEL: test_builtin_rdtscp
+; CHECK: rdtscp
+; X86-NOT: shlq
+; CHECK:   movl	%ecx, (%{{[a-z]+}})
+; X86-NOT: shlq
+; CHECK: ret
+
+
+declare i64 @llvm.readcyclecounter()
+declare i64 @llvm.x86.rdtscp(i8*)
+declare i64 @llvm.x86.rdtsc()
+