From 688dd45c474742aa9215ea44b8c818272f6948af Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Sat, 19 Dec 2015 02:54:15 +0000
Subject: [PATCH] AMDGPU/SI: Fix implemenation of isSourceOfDivergence() for
 graphics shaders

Summary:
The analysis of shader inputs was completely wrong.  We were passing the
wrong index to AttributeSet::hasAttribute() and the logic for which
inputs where in SGPRs was wrong too.

Reviewers: arsenm

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15608

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256082 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp  | 11 +++++------
 .../DivergenceAnalysis/AMDGPU/kernel-args.ll     | 16 ++++++++++++++++
 .../DivergenceAnalysis/AMDGPU/lit.local.cfg      |  2 ++
 3 files changed, 23 insertions(+), 6 deletions(-)
 create mode 100644 test/Analysis/DivergenceAnalysis/AMDGPU/kernel-args.ll
 create mode 100644 test/Analysis/DivergenceAnalysis/AMDGPU/lit.local.cfg

diff --git a/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp b/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
index eb9e837d291..c20a66e4481 100644
--- a/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
+++ b/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
@@ -141,14 +141,13 @@ static bool isArgPassedInSGPR(const Argument *A) {
   if (ShaderType == ShaderType::COMPUTE)
     return true;
 
-  // For non-compute shaders, the inreg attribute is used to mark inputs,
-  // which pre-loaded into SGPRs.
-  if (F->getAttributes().hasAttribute(A->getArgNo(), Attribute::InReg))
+  // For non-compute shaders, SGPR inputs are marked with either inreg or byval.
+  if (F->getAttributes().hasAttribute(A->getArgNo() + 1, Attribute::InReg) ||
+      F->getAttributes().hasAttribute(A->getArgNo() + 1, Attribute::ByVal))
     return true;
 
-  // For non-compute shaders, 32-bit values are pre-loaded into vgprs, all
-  // other value types use SGPRS.
-  return !A->getType()->isIntegerTy(32) && !A->getType()->isFloatTy();
+  // Everything else is in VGPRs.
+  return false;
 }
 
 ///
diff --git a/test/Analysis/DivergenceAnalysis/AMDGPU/kernel-args.ll b/test/Analysis/DivergenceAnalysis/AMDGPU/kernel-args.ll
new file mode 100644
index 00000000000..63e6c5c50de
--- /dev/null
+++ b/test/Analysis/DivergenceAnalysis/AMDGPU/kernel-args.ll
@@ -0,0 +1,16 @@
+; RUN: opt %s -mtriple amdgcn-- -analyze -divergence | FileCheck %s
+
+; CHECK: DIVERGENT:
+; CHECK-NOT: %arg0
+; CHECK-NOT: %arg1
+; CHECK-NOT; %arg2
+; CHECK: <2 x i32> %arg3
+; CHECK: DIVERGENT:  <3 x i32> %arg4
+; CHECK: DIVERGENT:  float %arg5
+; CHECK: DIVERGENT:  i32 %arg6
+
+define void @main([4 x <16 x i8>] addrspace(2)* byval %arg0, float inreg %arg1, i32 inreg %arg2, <2 x i32> %arg3, <3 x i32> %arg4, float %arg5, i32 %arg6) #0 {
+  ret void
+}
+
+attributes #0 = { "ShaderType"="0" }
diff --git a/test/Analysis/DivergenceAnalysis/AMDGPU/lit.local.cfg b/test/Analysis/DivergenceAnalysis/AMDGPU/lit.local.cfg
new file mode 100644
index 00000000000..2a665f06be7
--- /dev/null
+++ b/test/Analysis/DivergenceAnalysis/AMDGPU/lit.local.cfg
@@ -0,0 +1,2 @@
+if not 'AMDGPU' in config.root.targets:
+    config.unsupported = True
-- 
2.34.1