[Mesa-dev] [PATCH v2 1/2] R600/SI: Allow SI_KILL for geometry shaders

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---

v2:
* Bail in SILowerControlFlowPass::SkipIfDead() for geometry shaders, as
  the backend can't ensure M0 contains the proper value for S_SENDMSG by
  itself.
* Use just 'SI' as the lit test prefix.

 lib/Target/R600/SILowerControlFlow.cpp | 10 +++++++---
 test/CodeGen/R600/llvm.AMDGPU.kill.ll  | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)
 create mode 100644 test/CodeGen/R600/llvm.AMDGPU.kill.ll

diff --git a/lib/Target/R600/SILowerControlFlow.cpp b/lib/Target/R600/SILowerControlFlow.cpp
index f6f9016..fa5ee16 100644
--- a/lib/Target/R600/SILowerControlFlow.cpp
+++ b/lib/Target/R600/SILowerControlFlow.cpp
@@ -145,7 +145,9 @@ void SILowerControlFlowPass::SkipIfDead(MachineInstr &MI) {
   MachineBasicBlock &MBB = *MI.getParent();
   DebugLoc DL = MI.getDebugLoc();
 
-  if (!shouldSkip(&MBB, &MBB.getParent()->back()))
+  if (MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType !=
+      ShaderType::PIXEL ||
+      !shouldSkip(&MBB, &MBB.getParent()->back()))
     return;
 
   MachineBasicBlock::iterator Insert = &MI;
@@ -293,9 +295,11 @@ void SILowerControlFlowPass::Kill(MachineInstr &MI) {
   MachineBasicBlock &MBB = *MI.getParent();
   DebugLoc DL = MI.getDebugLoc();
 
-  // Kill is only allowed in pixel shaders
+  // Kill is only allowed in pixel / geometry shaders
   assert(MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType ==
-         ShaderType::PIXEL);
+         ShaderType::PIXEL ||
+         MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType ==
+         ShaderType::GEOMETRY);
 
   // Clear this pixel from the exec mask if the operand is negative
   BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMPX_LE_F32_e32), AMDGPU::VCC)
diff --git a/test/CodeGen/R600/llvm.AMDGPU.kill.ll b/test/CodeGen/R600/llvm.AMDGPU.kill.ll
new file mode 100644
index 0000000..bec5cdf
--- /dev/null
+++ b/test/CodeGen/R600/llvm.AMDGPU.kill.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -march=r600 -mcpu=verde -verify-machineinstrs | FileCheck --check-prefix=SI %s
+
+; SI-LABEL: @kill_gs
+; SI: V_CMPX_LE_F32
+
+define void @kill_gs() #0 {
+main_body:
+  %0 = icmp ule i32 0, 3
+  %1 = select i1 %0, float 1.000000e+00, float -1.000000e+00
+  call void @llvm.AMDGPU.kill(float %1)
+  ret void
+}
+
+declare void @llvm.AMDGPU.kill(float)
+
+attributes #0 = { "ShaderType"="2" }
+
+!0 = metadata !{metadata !"const", null, i32 1}
-- 
1.9.0