[PATCH] D38206: [InstCombine] Remove one use restriction on the shift for calls to foldICmpAndShift.

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This revision was automatically updated to reflect the committed changes.
Closed by commit rL314233: [InstCombine] Remove one use restriction on the shift for calls to… (authored by ctopper).

Repository:
  rL LLVM

https://reviews.llvm.org/D38206

Files:
  llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
  llvm/trunk/test/Transforms/InstCombine/icmp.ll


Index: llvm/trunk/test/Transforms/InstCombine/icmp.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp.ll
+++ llvm/trunk/test/Transforms/InstCombine/icmp.ll
@@ -1615,6 +1615,25 @@
   ret <2 x i1> %tobool
 }
 
+; Variation of the above with an extra use of the shift
+define i1 @icmp_and_shr_multiuse(i32 %X) {
+; CHECK-LABEL: @icmp_and_shr_multiuse(
+; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X:%.*]], 240
+; CHECK-NEXT:    [[AND2:%.*]] = and i32 [[X]], 496
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[AND]], 224
+; CHECK-NEXT:    [[TOBOOL2:%.*]] = icmp ne i32 [[AND2]], 432
+; CHECK-NEXT:    [[AND3:%.*]] = and i1 [[TOBOOL]], [[TOBOOL2]]
+; CHECK-NEXT:    ret i1 [[AND3]]
+;
+  %shr = lshr i32 %X, 4
+  %and = and i32 %shr, 15
+  %and2 = and i32 %shr, 31 ; second use of the shift
+  %tobool = icmp ne i32 %and, 14
+  %tobool2 = icmp ne i32 %and2, 27
+  %and3 = and i1 %tobool, %tobool2
+  ret i1 %and3
+}
+
 ; PR16244
 define i1 @test71(i8* %x) {
 ; CHECK-LABEL: @test71(
Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -1646,7 +1646,7 @@
   if (!match(And->getOperand(1), m_APInt(C2)))
     return nullptr;
 
-  if (!And->hasOneUse() || !And->getOperand(0)->hasOneUse())
+  if (!And->hasOneUse())
     return nullptr;
 
   // If the LHS is an 'and' of a truncate and we can widen the and/compare to
@@ -1658,7 +1658,7 @@
   // set or if it is an equality comparison. Extending a relational comparison
   // when we're checking the sign bit would not work.
   Value *W;
-  if (match(And->getOperand(0), m_Trunc(m_Value(W))) &&
+  if (match(And->getOperand(0), m_OneUse(m_Trunc(m_Value(W)))) &&
       (Cmp.isEquality() || (!C1->isNegative() && !C2->isNegative()))) {
     // TODO: Is this a good transform for vectors? Wider types may reduce
     // throughput. Should this transform be limited (even for scalars) by using
@@ -1680,7 +1680,7 @@
   // (icmp pred (and A, (or (shl 1, B), 1), 0))
   //
   // iff pred isn't signed
-  if (!Cmp.isSigned() && C1->isNullValue() &&
+  if (!Cmp.isSigned() && C1->isNullValue() && And->getOperand(0)->hasOneUse() &&
       match(And->getOperand(1), m_One())) {
     Constant *One = cast<Constant>(And->getOperand(1));
     Value *Or = And->getOperand(0);


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