[PATCH] D149416: [ValueTracking] Add logic for `isKnownNonZero(umin X, Y)`

[Noah Goldstein via Phabricator via llvm-commits]

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`(umin X, Y) != 0` -> `X != 0 && Y != 0`

Alive2 Link:

  https://alive2.llvm.org/ce/z/AQh67i


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D149416

Files:
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Analysis/ValueTracking/known-non-zero.ll


Index: llvm/test/Analysis/ValueTracking/known-non-zero.ll
===================================================================
--- llvm/test/Analysis/ValueTracking/known-non-zero.ll
+++ llvm/test/Analysis/ValueTracking/known-non-zero.ll
@@ -919,10 +919,7 @@
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[X_NZ]])
 ; CHECK-NEXT:    [[Y_NZ:%.*]] = icmp ne i8 [[YY:%.*]], 0
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[Y_NZ]])
-; CHECK-NEXT:    [[X:%.*]] = call i8 @llvm.umin.i8(i8 [[XX]], i8 [[YY]])
-; CHECK-NEXT:    [[Z:%.*]] = or i8 [[X]], [[IND:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[Z]], 0
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 false
 ;
   %x_nz = icmp ne i8 %xx, 0
   call void @llvm.assume(i1 %x_nz)
@@ -957,10 +954,7 @@
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[X_NZ]])
 ; CHECK-NEXT:    [[Y_NZ:%.*]] = icmp ne i8 [[YY:%.*]], 0
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[Y_NZ]])
-; CHECK-NEXT:    [[X:%.*]] = call i8 @llvm.umin.i8(i8 [[XX]], i8 [[YY]])
-; CHECK-NEXT:    [[Z:%.*]] = or i8 [[X]], [[IND:%.*]]
-; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[Z]], 0
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 false
 ;
   %x_nz = icmp ne i8 %xx, 0
   call void @llvm.assume(i1 %x_nz)
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -2926,6 +2926,9 @@
             isKnownNonZero(II->getArgOperand(1), DemandedElts, Depth, Q))
           return true;
         break;
+      case Intrinsic::umin:
+        return isKnownNonZero(II->getArgOperand(0), DemandedElts, Depth, Q) &&
+               isKnownNonZero(II->getArgOperand(1), DemandedElts, Depth, Q);
       case Intrinsic::cttz:
         return computeKnownBits(II->getArgOperand(0), DemandedElts, Depth, Q)
             .Zero[0];


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