[llvm] de885f1 - [InstCombine] Add (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0) vector support

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-10-19T15:41:21+01:00
New Revision: de885f1b2abe7fd26c22bbb551d1dc86a87e6dff

URL: https://github.com/llvm/llvm-project/commit/de885f1b2abe7fd26c22bbb551d1dc86a87e6dff
DIFF: https://github.com/llvm/llvm-project/commit/de885f1b2abe7fd26c22bbb551d1dc86a87e6dff.diff

LOG: [InstCombine] Add (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0) vector support

Scalar cases were already being handled by foldLogOpOfMaskedICmps (so this was dead code), but refactoring to support non-uniform vectors will take some time, so tweak this fold in the meantime.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    llvm/test/Transforms/InstCombine/icmp.ll

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 9b3e373f6a0e..c636cfaff4b5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2403,20 +2403,23 @@ Value *InstCombinerImpl::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
           foldUnsignedUnderflowCheck(RHS, LHS, /*IsAnd=*/false, Q, Builder))
     return X;
 
+  // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
+  // TODO: Remove this when foldLogOpOfMaskedICmps can handle vectors.
+  if (PredL == ICmpInst::ICMP_NE && match(LHS1, m_Zero()) &&
+      PredR == ICmpInst::ICMP_NE && match(RHS1, m_Zero()) &&
+      LHS0->getType()->isIntOrIntVectorTy() &&
+      LHS0->getType() == RHS0->getType()) {
+    Value *NewOr = Builder.CreateOr(LHS0, RHS0);
+    return Builder.CreateICmp(PredL, NewOr,
+                              Constant::getNullValue(NewOr->getType()));
+  }
+
   // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
   auto *LHSC = dyn_cast<ConstantInt>(LHS1);
   auto *RHSC = dyn_cast<ConstantInt>(RHS1);
   if (!LHSC || !RHSC)
     return nullptr;
 
-  if (LHSC == RHSC && PredL == PredR) {
-    // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
-    if (PredL == ICmpInst::ICMP_NE && LHSC->isZero()) {
-      Value *NewOr = Builder.CreateOr(LHS0, RHS0);
-      return Builder.CreateICmp(PredL, NewOr, LHSC);
-    }
-  }
-
   // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
   //   iff C2 + CA == C1.
   if (PredL == ICmpInst::ICMP_ULT && PredR == ICmpInst::ICMP_EQ) {

diff  --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll
index c6bfc29a15c1..80dd9d2b523d 100644
--- a/llvm/test/Transforms/InstCombine/icmp.ll
+++ b/llvm/test/Transforms/InstCombine/icmp.ll
@@ -2200,10 +2200,9 @@ define i1 @or_icmp_ne_A_0_icmp_ne_B_0(i64 %a, i64 %b) {
 
 define <2 x i1> @or_icmp_ne_A_0_icmp_ne_B_0_uniform(<2 x i64> %a, <2 x i64> %b) {
 ; CHECK-LABEL: @or_icmp_ne_A_0_icmp_ne_B_0_uniform(
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne <2 x i64> [[A:%.*]], zeroinitializer
-; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne <2 x i64> [[B:%.*]], zeroinitializer
-; CHECK-NEXT:    [[TMP3:%.*]] = or <2 x i1> [[TMP1]], [[TMP2]]
-; CHECK-NEXT:    ret <2 x i1> [[TMP3]]
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i64> [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne <2 x i64> [[TMP1]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[TMP2]]
 ;
   %1 = icmp ne <2 x i64> %a, zeroinitializer
   %2 = icmp ne <2 x i64> %b, zeroinitializer
@@ -2213,10 +2212,9 @@ define <2 x i1> @or_icmp_ne_A_0_icmp_ne_B_0_uniform(<2 x i64> %a, <2 x i64> %b)
 
 define <2 x i1> @or_icmp_ne_A_0_icmp_ne_B_0_undef(<2 x i64> %a, <2 x i64> %b) {
 ; CHECK-LABEL: @or_icmp_ne_A_0_icmp_ne_B_0_undef(
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne <2 x i64> [[A:%.*]], <i64 0, i64 undef>
-; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne <2 x i64> [[B:%.*]], <i64 0, i64 undef>
-; CHECK-NEXT:    [[TMP3:%.*]] = or <2 x i1> [[TMP1]], [[TMP2]]
-; CHECK-NEXT:    ret <2 x i1> [[TMP3]]
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i64> [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne <2 x i64> [[TMP1]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[TMP2]]
 ;
   %1 = icmp ne <2 x i64> %a, <i64 0, i64 undef>
   %2 = icmp ne <2 x i64> %b, <i64 0, i64 undef>