[PATCH] D119635: [NVPTX] Fix NVPTXReplaceImageHandles for multiple uses of a texref

[Dmitry Vassiliev via Phabricator via llvm-commits]

slydiman created this revision.
slydiman added reviewers: kazu, asavonic, krisb, gribozavr.
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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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D119635

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


Index: llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
===================================================================
--- llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
+++ llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
@@ -40,7 +40,35 @@
   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}
Index: llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
===================================================================
--- llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
+++ llvm/lib/Target/NVPTX/NVPTXReplaceImageHandles.cpp
@@ -64,8 +64,12 @@
   // 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;
 }
 


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