[llvm-branch-commits] [llvm-branch] r271769 - Merging r268259:

[Tom Stellard via llvm-branch-commits]

Author: tstellar
Date: Fri Jun  3 22:43:05 2016
New Revision: 271769

URL: http://llvm.org/viewvc/llvm-project?rev=271769&view=rev
Log:
Merging r268259:

------------------------------------------------------------------------
r268259 | nhaehnle | 2016-05-02 10:37:01 -0700 (Mon, 02 May 2016) | 14 lines

AMDGPU: llvm.SI.fs.constant is a source of divergence

Summary:
This intrinsic is used to get flat-shaded fragment shader inputs. Those are
uniform across a primitive, but a fragment shader wave may process pixels from
multiple primitives (as indicated by the prim_mask), and so that's where
divergence can arise.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D19747

------------------------------------------------------------------------

Added:
    llvm/branches/release_38/test/Analysis/DivergenceAnalysis/AMDGPU/interp-intrinsics.ll
Modified:
    llvm/branches/release_38/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp

Modified: llvm/branches/release_38/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp?rev=271769&r1=271768&r2=271769&view=diff
==============================================================================
--- llvm/branches/release_38/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp (original)
+++ llvm/branches/release_38/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp Fri Jun  3 22:43:05 2016
@@ -131,6 +131,7 @@ static bool isIntrinsicSourceOfDivergenc
     return false;
   case AMDGPUIntrinsic::SI_tid:
   case AMDGPUIntrinsic::SI_fs_interp:
+  case AMDGPUIntrinsic::SI_fs_constant:
     return true;
   }
 }

Added: llvm/branches/release_38/test/Analysis/DivergenceAnalysis/AMDGPU/interp-intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/test/Analysis/DivergenceAnalysis/AMDGPU/interp-intrinsics.ll?rev=271769&view=auto
==============================================================================
--- llvm/branches/release_38/test/Analysis/DivergenceAnalysis/AMDGPU/interp-intrinsics.ll (added)
+++ llvm/branches/release_38/test/Analysis/DivergenceAnalysis/AMDGPU/interp-intrinsics.ll Fri Jun  3 22:43:05 2016
@@ -0,0 +1,23 @@
+; RUN: opt  -mtriple amdgcn--- -analyze -divergence %s | FileCheck %s
+
+; CHECK-LABEL: 'fs_interp'
+; CHECK: DIVERGENT: %v = call float @llvm.SI.fs.interp(
+define void @fs_interp(i32 inreg %prim_mask, <2 x i32> %interp_param) #1 {
+  %v = call float @llvm.SI.fs.interp(i32 0, i32 0, i32 %prim_mask, <2 x i32> %interp_param)
+  store volatile float %v, float addrspace(1)* undef
+  ret void
+}
+
+; CHECK-LABEL: 'fs_constant'
+; CHECK: DIVERGENT: %v = call float @llvm.SI.fs.constant(
+define void @fs_constant(i32 inreg %prim_mask, <2 x i32> %interp_param) #1 {
+  %v = call float @llvm.SI.fs.constant(i32 0, i32 0, i32 %prim_mask)
+  store volatile float %v, float addrspace(1)* undef
+  ret void
+}
+
+declare float @llvm.SI.fs.interp(i32, i32, i32, <2 x i32>) #0
+declare float @llvm.SI.fs.constant(i32, i32, i32) #0
+
+attributes #0 = { nounwind readnone }
+attributes #1 = { "ShaderType"="1"}