[PATCH] D140405: [CVP] Simplify SRem when constantrange abs(lhs) < abs(rhs)

[luxufan via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG5b25a0bcb14b: [CVP] Simplify SRem when constantrange abs(lhs) < abs(rhs) (authored by StephenFan).

Changed prior to commit:
  https://reviews.llvm.org/D140405?vs=484472&id=485985#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140405/new/

https://reviews.llvm.org/D140405

Files:
  llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
  llvm/test/Transforms/CorrelatedValuePropagation/srem.ll


Index: llvm/test/Transforms/CorrelatedValuePropagation/srem.ll
===================================================================
--- llvm/test/Transforms/CorrelatedValuePropagation/srem.ll
+++ llvm/test/Transforms/CorrelatedValuePropagation/srem.ll
@@ -523,8 +523,7 @@
 ; CHECK-NEXT:    [[AND_COND:%.*]] = and i1 [[AND_X]], [[Y_CMP]]
 ; CHECK-NEXT:    br i1 [[AND_COND]], label [[IF_ELSE:%.*]], label [[IF_THEN:%.*]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[REM:%.*]] = srem i8 [[X]], [[Y]]
-; CHECK-NEXT:    ret i8 [[REM]]
+; CHECK-NEXT:    ret i8 [[X]]
 ; CHECK:       if.then:
 ; CHECK-NEXT:    ret i8 0
 ;
@@ -556,8 +555,7 @@
 ; CHECK-NEXT:    [[AND_COND:%.*]] = and i1 [[AND_X]], [[AND_Y]]
 ; CHECK-NEXT:    br i1 [[AND_COND]], label [[IF_ELSE:%.*]], label [[IF_THEN:%.*]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[REM:%.*]] = srem i8 [[X]], [[Y]]
-; CHECK-NEXT:    ret i8 [[REM]]
+; CHECK-NEXT:    ret i8 [[X]]
 ; CHECK:       if.then:
 ; CHECK-NEXT:    ret i8 0
 ;
@@ -591,8 +589,7 @@
 ; CHECK-NEXT:    [[AND_COND:%.*]] = and i1 [[AND_X]], [[AND_Y]]
 ; CHECK-NEXT:    br i1 [[AND_COND]], label [[IF_ELSE:%.*]], label [[IF_THEN:%.*]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[REM:%.*]] = srem i8 [[X]], [[Y]]
-; CHECK-NEXT:    ret i8 [[REM]]
+; CHECK-NEXT:    ret i8 [[X]]
 ; CHECK:       if.then:
 ; CHECK-NEXT:    ret i8 0
 ;
Index: llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -905,6 +905,15 @@
   if (SDI->getType()->isVectorTy())
     return false;
 
+  ConstantRange LCR = LVI->getConstantRange(SDI->getOperand(0), SDI);
+  ConstantRange RCR = LVI->getConstantRange(SDI->getOperand(1), SDI);
+
+  if (LCR.abs().icmp(CmpInst::ICMP_ULT, RCR.abs())) {
+    SDI->replaceAllUsesWith(SDI->getOperand(0));
+    SDI->eraseFromParent();
+    return true;
+  }
+
   struct Operand {
     Value *V;
     Domain D;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D140405.485985.patch
Type: text/x-patch
Size: 2035 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230103/21f6f5e0/attachment.bin>