[llvm] 66c18c7 - [X86][SSE] Combine PTEST(AND(X,Y),AND(X,Y)) -> PTEST(X,Y) and ANDN equivalents

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-04-08T12:42:22+01:00
New Revision: 66c18c729da456680af7884f551a6c4627dc6372

URL: https://github.com/llvm/llvm-project/commit/66c18c729da456680af7884f551a6c4627dc6372
DIFF: https://github.com/llvm/llvm-project/commit/66c18c729da456680af7884f551a6c4627dc6372.diff

LOG: [X86][SSE] Combine PTEST(AND(X,Y),AND(X,Y)) -> PTEST(X,Y) and ANDN equivalents

Tests derived from PR42035 examples

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/test/CodeGen/X86/combine-ptest.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index c89e4ac3e899..175b90c7fc4c 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -39930,6 +39930,25 @@ static SDValue combinePTESTCC(SDValue EFLAGS, X86::CondCode &CC,
                          DAG.getBitcast(OpVT, NotOp1), Op0);
     }
 
+    if (Op0 == Op1) {
+      SDValue BC = peekThroughBitcasts(Op0);
+
+      // TESTZ(AND(X,Y),AND(X,Y)) == TESTZ(X,Y)
+      if (BC.getOpcode() == ISD::AND || BC.getOpcode() == X86ISD::FAND) {
+        return DAG.getNode(EFLAGS.getOpcode(), SDLoc(EFLAGS), VT,
+                           DAG.getBitcast(OpVT, BC.getOperand(0)),
+                           DAG.getBitcast(OpVT, BC.getOperand(1)));
+      }
+
+      // TESTZ(AND(~X,Y),AND(~X,Y)) == TESTC(X,Y)
+      if (BC.getOpcode() == X86ISD::ANDNP || BC.getOpcode() == X86ISD::FANDN) {
+        CC = (CC == X86::COND_E ? X86::COND_B : X86::COND_AE);
+        return DAG.getNode(EFLAGS.getOpcode(), SDLoc(EFLAGS), VT,
+                           DAG.getBitcast(OpVT, BC.getOperand(0)),
+                           DAG.getBitcast(OpVT, BC.getOperand(1)));
+      }
+    }
+
     // TESTZ(-1,X) == TESTZ(X,X)
     if (ISD::isBuildVectorAllOnes(Op0.getNode()))
       return DAG.getNode(EFLAGS.getOpcode(), SDLoc(EFLAGS), VT, Op1, Op1);

diff  --git a/llvm/test/CodeGen/X86/combine-ptest.ll b/llvm/test/CodeGen/X86/combine-ptest.ll
index 0ae16f17f039..d23277f62768 100644
--- a/llvm/test/CodeGen/X86/combine-ptest.ll
+++ b/llvm/test/CodeGen/X86/combine-ptest.ll
@@ -156,8 +156,7 @@ define i32 @ptestz_128_and(<2 x i64> %c, <2 x i64> %d, i32 %a, i32 %b) {
 ; CHECK-LABEL: ptestz_128_and:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    vpand %xmm1, %xmm0, %xmm0
-; CHECK-NEXT:    vptest %xmm0, %xmm0
+; CHECK-NEXT:    vptest %xmm1, %xmm0
 ; CHECK-NEXT:    cmovnel %esi, %eax
 ; CHECK-NEXT:    retq
   %t1 = and <2 x i64> %c, %d
@@ -171,8 +170,7 @@ define i32 @ptestz_256_and(<4 x i64> %c, <4 x i64> %d, i32 %a, i32 %b) {
 ; CHECK-LABEL: ptestz_256_and:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    vandps %ymm1, %ymm0, %ymm0
-; CHECK-NEXT:    vptest %ymm0, %ymm0
+; CHECK-NEXT:    vptest %ymm1, %ymm0
 ; CHECK-NEXT:    cmovel %esi, %eax
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    retq
@@ -191,9 +189,8 @@ define i32 @ptestz_128_andc(<2 x i64> %c, <2 x i64> %d, i32 %a, i32 %b) {
 ; CHECK-LABEL: ptestz_128_andc:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    vpandn %xmm1, %xmm0, %xmm0
-; CHECK-NEXT:    vptest %xmm0, %xmm0
-; CHECK-NEXT:    cmovnel %esi, %eax
+; CHECK-NEXT:    vptest %xmm1, %xmm0
+; CHECK-NEXT:    cmovael %esi, %eax
 ; CHECK-NEXT:    retq
   %t1 = xor <2 x i64> %c, <i64 -1, i64 -1>
   %t2 = and <2 x i64> %t1, %d
@@ -207,9 +204,8 @@ define i32 @ptestz_256_andc(<4 x i64> %c, <4 x i64> %d, i32 %a, i32 %b) {
 ; CHECK-LABEL: ptestz_256_andc:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    vandnps %ymm1, %ymm0, %ymm0
-; CHECK-NEXT:    vptest %ymm0, %ymm0
-; CHECK-NEXT:    cmovel %esi, %eax
+; CHECK-NEXT:    vptest %ymm1, %ymm0
+; CHECK-NEXT:    cmovbl %esi, %eax
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    retq
   %t1 = xor <4 x i64> %c, <i64 -1, i64 -1, i64 -1, i64 -1>