[Inliner] Don't inline if target-cpu and target-features attribute strings don't match exactly

[ahatanak]

Summary

This patch makes changes to InlineCostAnalysis to prevent inlining functions that don't have exactly the same target-cpu and target-features attribute strings as the caller function.

This is a temporary solution until we come up with a better design for attributes (see this link: http://reviews.llvm.org/D7802).

[chandlerc]

Thanks, this looks like a great temporary fix LTO folks can go back to making progress.

llvm/trunk/lib/Analysis/IPA/InlineCost.cpp

 }
 
 InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
   return getInlineCost(CS, CS.getCalledFunction(), Threshold);
 }
 
 /// \brief Test that two functions either have or have not the given attribute
 ///        at the same time.
-static bool attributeMatches(Function *F1, Function *F2,
-                             Attribute::AttrKind Attr) {
-  return F1->hasFnAttribute(Attr) == F2->hasFnAttribute(Attr);
+template<typename AttrKind>
+static bool attributeMatches(Function *F1, Function *F2, AttrKind Attr) {
+  return F1->getFnAttribute(Attr) == F2->getFnAttribute(Attr);
 }
 
 /// \brief Test that there are no attribute conflicts between Caller and Callee
 ///        that prevent inlining.
 static bool functionsHaveCompatibleAttributes(Function *Caller,
                                               Function *Callee) {
-  return attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
+  return attributeMatches(Caller, Callee, "target-cpu") &&
+         attributeMatches(Caller, Callee, "target-features") &&
+         attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
          attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
          attributeMatches(Caller, Callee, Attribute::SanitizeThread);
 }
 
 InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
                                              int Threshold) {
   // Cannot inline indirect calls.
   if (!Callee)

llvm/trunk/test/Transforms/Inline/attributes.ll

define i32 @test_sanitize_thread(i32 %arg) sanitize_thread {
   %x2 = call i32 @sanitize_thread_callee(i32 %x1)
   %x3 = call i32 @alwaysinline_callee(i32 %x2)
   %x4 = call i32 @alwaysinline_sanitize_thread_callee(i32 %x3)
   ret i32 %x4
 ; CHECK-LABEL: @test_sanitize_thread(
 ; CHECK-NEXT: @noattr_callee
 ; CHECK-NEXT: ret i32
 }
+
+; Check that a function doesn't get inlined if target-cpu strings don't match
+; exactly.
+define i32 @test_target_cpu_callee0(i32 %i) "target-cpu"="corei7" {
+  ret i32 %i
+}
+
+define i32 @test_target_cpu0(i32 %i) "target-cpu"="corei7" {
+  %1 = call i32 @test_target_cpu_callee0(i32 %i)
+  ret i32 %1
+; CHECK-LABEL: @test_target_cpu0(
+; CHECK-NOT: @test_target_cpu_callee0
+}
+
+define i32 @test_target_cpu_callee1(i32 %i) "target-cpu"="x86-64" {
+  ret i32 %i
+}
+
+define i32 @test_target_cpu1(i32 %i) "target-cpu"="corei7" {
+  %1 = call i32 @test_target_cpu_callee1(i32 %i)
+  ret i32 %1
+; CHECK-LABEL: @test_target_cpu1(
+; CHECK-NEXT: @test_target_cpu_callee1
+; CHECK-NEXT: ret i32
+}
+
+; Check that a function doesn't get inlined if target-features strings don't
+; match exactly.
+define i32 @test_target_features_callee0(i32 %i)  "target-features"="+sse4.2" {
+  ret i32 %i
+}
+
+define i32 @test_target_features0(i32 %i) "target-features"="+sse4.2" {
+  %1 = call i32 @test_target_features_callee0(i32 %i)
+  ret i32 %1
+; CHECK-LABEL: @test_target_features0(
+; CHECK-NOT: @test_target_features_callee0
+}
+
+define i32 @test_target_features_callee1(i32 %i) "target-features"="+avx2" {
+  ret i32 %i
+}
+
+define i32 @test_target_features1(i32 %i) "target-features"="+sse4.2" {
+  %1 = call i32 @test_target_features_callee1(i32 %i)
+  ret i32 %1
+; CHECK-LABEL: @test_target_features1(
+; CHECK-NEXT: @test_target_features_callee1
+; CHECK-NEXT: ret i32
+}