[llvm-commits] [llvm] r169727 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/fold-pcmpeqd-2.ll test/CodeGen/X86/vec_zero.ll

[Craig Topper]

Author: ctopper
Date: Mon Dec 10 02:12:29 2012
New Revision: 169727

URL: http://llvm.org/viewvc/llvm-project?rev=169727&view=rev
Log:
Teach DAG combine to handle vector add/sub with vectors of all 0s.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/trunk/test/CodeGen/X86/fold-pcmpeqd-2.ll
    llvm/trunk/test/CodeGen/X86/vec_zero.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=169727&r1=169726&r2=169727&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Dec 10 02:12:29 2012
@@ -1381,6 +1381,12 @@
   if (VT.isVector()) {
     SDValue FoldedVOp = SimplifyVBinOp(N);
     if (FoldedVOp.getNode()) return FoldedVOp;
+
+    // fold (add x, 0) -> x, vector edition
+    if (ISD::isBuildVectorAllZeros(N1.getNode()))
+      return N0;
+    if (ISD::isBuildVectorAllZeros(N0.getNode()))
+      return N1;
   }
 
   // fold (add x, undef) -> undef
@@ -1624,6 +1630,10 @@
   if (VT.isVector()) {
     SDValue FoldedVOp = SimplifyVBinOp(N);
     if (FoldedVOp.getNode()) return FoldedVOp;
+
+    // fold (sub x, 0) -> x, vector edition
+    if (ISD::isBuildVectorAllZeros(N1.getNode()))
+      return N0;
   }
 
   // fold (sub x, x) -> 0

Modified: llvm/trunk/test/CodeGen/X86/fold-pcmpeqd-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fold-pcmpeqd-2.ll?rev=169727&r1=169726&r2=169727&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fold-pcmpeqd-2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fold-pcmpeqd-2.ll Mon Dec 10 02:12:29 2012
@@ -43,11 +43,11 @@
 	%mul171.i = fmul <4 x float> %add167.i, %sub140.i		; <<4 x float>> [#uses=1]
 	%add172.i = fadd <4 x float> %mul171.i, < float 0x3FF0000A40000000, float 0x3FF0000A40000000, float 0x3FF0000A40000000, float 0x3FF0000A40000000 >		; <<4 x float>> [#uses=1]
 	%bitcast176.i = bitcast <4 x float> %add172.i to <4 x i32>		; <<4 x i32>> [#uses=1]
-	%andnps178.i = add <4 x i32> %bitcast176.i, zeroinitializer		; <<4 x i32>> [#uses=1]
+	%andnps178.i = add <4 x i32> %bitcast176.i, <i32 1, i32 1, i32 1, i32 1>		; <<4 x i32>> [#uses=1]
 	%bitcast179.i = bitcast <4 x i32> %andnps178.i to <4 x float>		; <<4 x float>> [#uses=1]
 	%mul186.i = fmul <4 x float> %bitcast179.i, zeroinitializer		; <<4 x float>> [#uses=1]
 	%bitcast190.i = bitcast <4 x float> %mul186.i to <4 x i32>		; <<4 x i32>> [#uses=1]
-	%andnps192.i = add <4 x i32> %bitcast190.i, zeroinitializer		; <<4 x i32>> [#uses=1]
+	%andnps192.i = add <4 x i32> %bitcast190.i, <i32 1, i32 1, i32 1, i32 1>		; <<4 x i32>> [#uses=1]
 	%xorps.i = xor <4 x i32> zeroinitializer, < i32 -1, i32 -1, i32 -1, i32 -1 >		; <<4 x i32>> [#uses=1]
 	%orps203.i = add <4 x i32> %andnps192.i, %xorps.i		; <<4 x i32>> [#uses=1]
 	%bitcast204.i = bitcast <4 x i32> %orps203.i to <4 x float>		; <<4 x float>> [#uses=1]
@@ -55,9 +55,9 @@
 	%mul313 = fmul <4 x float> %bitcast204.i, zeroinitializer		; <<4 x float>> [#uses=1]
 	%cmpunord.i11 = call <4 x float> @llvm.x86.sse.cmp.ps(<4 x float> zeroinitializer, <4 x float> zeroinitializer, i8 3) nounwind		; <<4 x float>> [#uses=1]
 	%bitcast6.i13 = bitcast <4 x float> %cmpunord.i11 to <4 x i32>		; <<4 x i32>> [#uses=2]
-	%andps.i14 = add <4 x i32> zeroinitializer, %bitcast6.i13		; <<4 x i32>> [#uses=1]
+	%andps.i14 = add <4 x i32> <i32 1, i32 1, i32 1, i32 1>, %bitcast6.i13		; <<4 x i32>> [#uses=1]
 	%not.i16 = xor <4 x i32> %bitcast6.i13, < i32 -1, i32 -1, i32 -1, i32 -1 >		; <<4 x i32>> [#uses=1]
-	%andnps.i17 = add <4 x i32> zeroinitializer, %not.i16		; <<4 x i32>> [#uses=1]
+	%andnps.i17 = add <4 x i32> <i32 1, i32 1, i32 1, i32 1>, %not.i16		; <<4 x i32>> [#uses=1]
 	%orps.i18 = or <4 x i32> %andnps.i17, %andps.i14		; <<4 x i32>> [#uses=1]
 	%bitcast17.i19 = bitcast <4 x i32> %orps.i18 to <4 x float>		; <<4 x float>> [#uses=1]
 	%tmp83 = call <4 x float> @llvm.x86.sse.min.ps(<4 x float> %mul310, <4 x float> zeroinitializer) nounwind		; <<4 x float>> [#uses=1]

Modified: llvm/trunk/test/CodeGen/X86/vec_zero.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_zero.ll?rev=169727&r1=169726&r2=169727&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_zero.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_zero.ll Mon Dec 10 02:12:29 2012
@@ -13,7 +13,7 @@
 ; CHECK: pxor
 define void @bar(<4 x i32>* %P) {
         %T = load <4 x i32>* %P         ; <<4 x i32>> [#uses=1]
-        %S = add <4 x i32> zeroinitializer, %T          ; <<4 x i32>> [#uses=1]
+        %S = sub <4 x i32> zeroinitializer, %T          ; <<4 x i32>> [#uses=1]
         store <4 x i32> %S, <4 x i32>* %P
         ret void
 }