[llvm] 8851401 - [NVPTX] Fix NVPTXReplaceImageHandles for multiple uses of a texref

[Dmitry Vassiliev via llvm-commits]

Author: Dmitry Vassiliev
Date: 2022-02-15T01:30:13+03:00
New Revision: 885140171a7607910aa1f76860103fee3a830ce1

URL: https://github.com/llvm/llvm-project/commit/885140171a7607910aa1f76860103fee3a830ce1
DIFF: https://github.com/llvm/llvm-project/commit/885140171a7607910aa1f76860103fee3a830ce1.diff

LOG: [NVPTX] Fix NVPTXReplaceImageHandles for multiple uses of a texref

The texsurf_handle is removed by NVPTXReplaceImageHandles.cpp. There are more than one uses of the texsurf_handle, one of them is a regular function call, and one of them is a texture intrinsic.
The current hacky logic in NVPTXReplaceImageHandles.cpp for CUDA cannot handle such a mixed use. This patch fixes this issue.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D119635

Added: 
    

Modified: 
    llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
    llvm/test/CodeGen/NVPTX/tex-read-cuda.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp b/llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
index f4934f0bc20b1..4bd820e98f050 100644
--- a/llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
@@ -64,8 +64,12 @@ bool NVPTXReplaceImageHandles::runOnMachineFunction(MachineFunction &MF) {
   // This is needed in debug mode when code cleanup passes are not executed,
   // but we need the handle access to be eliminated because they are not
   // valid instructions when image handles are disabled.
-  for (MachineInstr *MI : InstrsToRemove)
-    MI->eraseFromParent();
+  for (MachineInstr *MI : InstrsToRemove) {
+    unsigned DefReg = MI->getOperand(0).getReg();
+    // Only these that are not used can be removed.
+    if (MF.getRegInfo().use_nodbg_empty(DefReg))
+      MI->eraseFromParent();
+  }
   return Changed;
 }
 

diff  --git a/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll b/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
index 09d2ff0967378..5a8261ce15fe7 100644
--- a/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
+++ b/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
@@ -40,7 +40,35 @@ define void @bar(float* %red, i32 %idx) {
   ret void
 }
 
-!nvvm.annotations = !{!1, !2, !3}
+declare float @texfunc(i64)
+
+; SM20-LABEL: .entry baz
+; SM30-LABEL: .entry baz
+define void @baz(float* %red, i32 %idx) {
+; SM30: mov.u64 %rd[[TEXHANDLE:[0-9]+]], tex0
+  %texHandle = tail call i64 @llvm.nvvm.texsurf.handle.internal.p1i64(i64 addrspace(1)* @tex0)
+; SM20: tex.1d.v4.f32.s32 {%f[[RED:[0-9]+]], %f[[GREEN:[0-9]+]], %f[[BLUE:[0-9]+]], %f[[ALPHA:[0-9]+]]}, [tex0, {%r{{[0-9]+}}}]
+; SM30: tex.1d.v4.f32.s32 {%f[[RED:[0-9]+]], %f[[GREEN:[0-9]+]], %f[[BLUE:[0-9]+]], %f[[ALPHA:[0-9]+]]}, [%rd[[TEXHANDLE]], {%r{{[0-9]+}}}]
+  %val = tail call { float, float, float, float } @llvm.nvvm.tex.unified.1d.v4f32.s32(i64 %texHandle, i32 %idx)
+  %ret = extractvalue { float, float, float, float } %val, 0
+; SM20: call.uni ([[RETVAL:.*]]),
+; SM30: call.uni ([[RETVAL:.*]]),
+; SM20: texfunc,
+; SM30: texfunc,
+  %texcall = tail call float @texfunc(i64 %texHandle)
+; SM20: ld.param.f32 %f[[TEXCALL:[0-9]+]], [[[RETVAL]]+0]
+; SM30: ld.param.f32 %f[[TEXCALL:[0-9]+]], [[[RETVAL]]+0]
+; SM20: add.rn.f32 %f[[RET2:[0-9]+]], %f[[RED]], %f[[TEXCALL]]
+; SM30: add.rn.f32 %f[[RET2:[0-9]+]], %f[[RED]], %f[[TEXCALL]]
+  %ret2 = fadd float %ret, %texcall
+; SM20: st.global.f32 [%r{{[0-9]+}}], %f[[RET2]]
+; SM30: st.global.f32 [%r{{[0-9]+}}], %f[[RET2]]
+  store float %ret2, float* %red
+  ret void
+}
+
+!nvvm.annotations = !{!1, !2, !3, !4}
 !1 = !{void (i64, float*, i32)* @foo, !"kernel", i32 1}
 !2 = !{void (float*, i32)* @bar, !"kernel", i32 1}
 !3 = !{i64 addrspace(1)* @tex0, !"texture", i32 1}
+!4 = !{void (float*, i32)* @baz, !"kernel", i32 1}