Author: ctopper Date: Fri Oct 19 18:30:00 2018 New Revision: 344824 URL: http://llvm.org/viewvc/llvm-project?rev=344824&view=rev Log: [X86] When checking the bits in cpu_features for function multiversioning dispatcher in the resolver, make sure all the required bits are set. Not just one of them
Summary: The multiversioning code repurposed the code from __builtin_cpu_supports for checking if a single feature is enabled. That code essentially performed (_cpu_features & (1 << C)) != 0. But with the multiversioning path, the mask is no longer guaranteed to be a power of 2. So we return true anytime any one of the bits in the mask is set not just all of the bits. The correct check is (_cpu_features & mask) == mask Reviewers: erichkeane, echristo Reviewed By: echristo Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D53460 Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp cfe/trunk/test/CodeGen/attr-target-mv.c cfe/trunk/test/CodeGen/builtin-cpu-supports.c Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=344824&r1=344823&r2=344824&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original) +++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Fri Oct 19 18:30:00 2018 @@ -9129,9 +9129,9 @@ llvm::Value *CodeGenFunction::EmitX86Cpu Builder.CreateAlignedLoad(CpuFeatures, CharUnits::fromQuantity(4)); // Check the value of the bit corresponding to the feature requested. - Value *Bitset = Builder.CreateAnd( - Features, llvm::ConstantInt::get(Int32Ty, FeaturesMask)); - return Builder.CreateICmpNE(Bitset, llvm::ConstantInt::get(Int32Ty, 0)); + Value *Mask = Builder.getInt32(FeaturesMask); + Value *Bitset = Builder.CreateAnd(Features, Mask); + return Builder.CreateICmpEQ(Bitset, Mask); } Value *CodeGenFunction::EmitX86CpuInit() { Modified: cfe/trunk/test/CodeGen/attr-target-mv.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/attr-target-mv.c?rev=344824&r1=344823&r2=344824&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/attr-target-mv.c (original) +++ cfe/trunk/test/CodeGen/attr-target-mv.c Fri Oct 19 18:30:00 2018 @@ -70,6 +70,22 @@ void bar4() { // CHECK: ret void ()* @foo_decls.sse4.2 // CHECK: ret void ()* @foo_decls +// CHECK: define void @bar4() +// CHECK: call void @foo_multi.ifunc() + +// CHECK: define void ()* @foo_multi.resolver() comdat +// CHECK: and i32 %{{.*}}, 4352 +// CHECK: icmp eq i32 %{{.*}}, 4352 +// CHECK: ret void ()* @foo_multi.fma4_sse4.2 +// CHECK: icmp eq i32 %{{.*}}, 12 +// CHECK: and i32 %{{.*}}, 4352 +// CHECK: icmp eq i32 %{{.*}}, 4352 +// CHECK: ret void ()* @foo_multi.arch_ivybridge_fma4_sse4.2 +// CHECK: and i32 %{{.*}}, 768 +// CHECK: icmp eq i32 %{{.*}}, 768 +// CHECK: ret void ()* @foo_multi.avx_sse4.2 +// CHECK: ret void ()* @foo_multi + // CHECK: declare i32 @foo.arch_sandybridge() // CHECK: define available_externally i32 @foo_inline.sse4.2() @@ -88,4 +104,3 @@ void bar4() { // CHECK: define available_externally void @foo_multi.avx_sse4.2() // CHECK: define available_externally void @foo_multi.fma4_sse4.2() // CHECK: define available_externally void @foo_multi.arch_ivybridge_fma4_sse4.2() - Modified: cfe/trunk/test/CodeGen/builtin-cpu-supports.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/builtin-cpu-supports.c?rev=344824&r1=344823&r2=344824&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/builtin-cpu-supports.c (original) +++ cfe/trunk/test/CodeGen/builtin-cpu-supports.c Fri Oct 19 18:30:00 2018 @@ -14,7 +14,7 @@ int main() { // CHECK: [[LOAD:%[^ ]+]] = load i32, i32* getelementptr inbounds ({ i32, i32, i32, [1 x i32] }, { i32, i32, i32, [1 x i32] }* @__cpu_model, i32 0, i32 3, i32 0) // CHECK: [[AND:%[^ ]+]] = and i32 [[LOAD]], 256 - // CHECK: = icmp ne i32 [[AND]], 0 + // CHECK: = icmp eq i32 [[AND]], 256 return 0; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
