[PATCH] D25493: [PPCMIPeephole] Fix splat elimination

[Tim Shen via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL283961: [PPCMIPeephole] Fix splat elimination (authored by timshen).

Changed prior to commit:
  https://reviews.llvm.org/D25493?vs=74313&id=74336#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D25493

Files:
  llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp
  llvm/trunk/test/CodeGen/PowerPC/pr30663.ll


Index: llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp
===================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp
+++ llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp
@@ -201,11 +201,13 @@
         // Splat fed by another splat - switch the output of the first
         // and remove the second.
         if (SameOpcode) {
-          DefMI->getOperand(0).setReg(MI.getOperand(0).getReg());
+          DEBUG(dbgs() << "Changing redundant splat to a copy: ");
+          DEBUG(MI.dump());
+          BuildMI(MBB, &MI, MI.getDebugLoc(), TII->get(PPC::COPY),
+                  MI.getOperand(0).getReg())
+              .addOperand(MI.getOperand(OpNo));
           ToErase = &MI;
           Simplified = true;
-          DEBUG(dbgs() << "Removing redundant splat: ");
-          DEBUG(MI.dump());
         }
         // Splat fed by a shift. Usually when we align value to splat into
         // vector element zero.
Index: llvm/trunk/test/CodeGen/PowerPC/pr30663.ll
===================================================================
--- llvm/trunk/test/CodeGen/PowerPC/pr30663.ll
+++ llvm/trunk/test/CodeGen/PowerPC/pr30663.ll
@@ -0,0 +1,24 @@
+; RUN: llc -O1 < %s | FileCheck %s
+target triple = "powerpc64le-linux-gnu"
+
+; The second xxspltw should be eliminated.
+; CHECK: xxspltw
+; CHECK-NOT: xxspltw
+define void @Test() {
+bb4:
+  %tmp = load <4 x i8>, <4 x i8>* undef
+  %tmp8 = bitcast <4 x i8> %tmp to float
+  %tmp18 = fmul float %tmp8, undef
+  %tmp19 = fsub float 0.000000e+00, %tmp18
+  store float %tmp19, float* undef
+  %tmp22 = shufflevector <4 x i8> %tmp, <4 x i8> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
+  %tmp23 = bitcast <16 x i8> %tmp22 to <4 x float>
+  %tmp25 = tail call <4 x float> @llvm.fma.v4f32(<4 x float> undef, <4 x float> %tmp23, <4 x float> undef)
+  %tmp26 = fsub <4 x float> zeroinitializer, %tmp25
+  %tmp27 = bitcast <4 x float> %tmp26 to <4 x i32>
+  tail call void @llvm.ppc.altivec.stvx(<4 x i32> %tmp27, i8* undef)
+  ret void
+}
+
+declare void @llvm.ppc.altivec.stvx(<4 x i32>, i8*)
+declare <4 x float> @llvm.fma.v4f32(<4 x float>, <4 x float>, <4 x float>)


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