[llvm] d3e3f36 - Revert "[ScalarEvolution] createSCEV(): recognize `udiv`/`urem` disguised as an `sdiv`/`srem`"

Kadir Cetinkaya via llvm-commits llvm-commits at lists.llvm.org
Mon Jul 6 07:42:32 PDT 2020


Author: Mikhail Goncharov
Date: 2020-07-06T16:41:59+02:00
New Revision: d3e3f36ff1151f565730977ac4f663a2ccee48ae

URL: https://github.com/llvm/llvm-project/commit/d3e3f36ff1151f565730977ac4f663a2ccee48ae
DIFF: https://github.com/llvm/llvm-project/commit/d3e3f36ff1151f565730977ac4f663a2ccee48ae.diff

LOG: Revert "[ScalarEvolution] createSCEV(): recognize `udiv`/`urem` disguised as an `sdiv`/`srem`"

Summary:
This reverts commit 2c16100e6f72075564ea1f67fa5a82c269dafcd3.

ninja check-polly fails:
  Polly :: Isl/CodeGen/MemAccess/generate-all.ll
  Polly :: ScopInfo/multidim_srem.ll

Reviewers: kadircet, bollu

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83230

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp
    llvm/test/Analysis/ScalarEvolution/sdiv.ll
    llvm/test/Analysis/ScalarEvolution/srem.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 75926aa3a960..609ad639d9c0 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -6303,20 +6303,6 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) {
       return getSCEV(U->getOperand(0));
     break;
 
-  case Instruction::SDiv:
-    // If both operands are non-negative, this is just an udiv.
-    if (isKnownNonNegative(getSCEV(U->getOperand(0))) &&
-        isKnownNonNegative(getSCEV(U->getOperand(1))))
-      return getUDivExpr(getSCEV(U->getOperand(0)), getSCEV(U->getOperand(1)));
-    break;
-
-  case Instruction::SRem:
-    // If both operands are non-negative, this is just an urem.
-    if (isKnownNonNegative(getSCEV(U->getOperand(0))) &&
-        isKnownNonNegative(getSCEV(U->getOperand(1))))
-      return getURemExpr(getSCEV(U->getOperand(0)), getSCEV(U->getOperand(1)));
-    break;
-
   // It's tempting to handle inttoptr and ptrtoint as no-ops, however this can
   // lead to pointer expressions which cannot safely be expanded to GEPs,
   // because ScalarEvolution doesn't respect the GEP aliasing rules when

diff  --git a/llvm/test/Analysis/ScalarEvolution/sdiv.ll b/llvm/test/Analysis/ScalarEvolution/sdiv.ll
index 106cda1b7f0f..b4895855ab71 100644
--- a/llvm/test/Analysis/ScalarEvolution/sdiv.ll
+++ b/llvm/test/Analysis/ScalarEvolution/sdiv.ll
@@ -14,11 +14,11 @@ define dso_local void @_Z4loopi(i32 %width) local_unnamed_addr #0 {
 ; CHECK-NEXT:    %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
 ; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%for.cond> U: [0,-2147483648) S: [0,-2147483648) Exits: %width LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %rem = sdiv i32 %i.0, 2
-; CHECK-NEXT:    --> ({0,+,1}<nuw><nsw><%for.cond> /u 2) U: [0,1073741824) S: [0,1073741824) Exits: (%width /u 2) LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> %rem U: full-set S: [-1073741824,1073741824) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %idxprom = sext i32 %rem to i64
-; CHECK-NEXT:    --> ({0,+,1}<nuw><nsw><%for.cond> /u 2) U: [0,2147483648) S: [0,2147483648) Exits: ((zext i32 %width to i64) /u 2) LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> (sext i32 %rem to i64) U: [-2147483648,2147483648) S: [-1073741824,1073741824) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %arrayidx = getelementptr inbounds [2 x i32], [2 x i32]* %storage, i64 0, i64 %idxprom
-; CHECK-NEXT:    --> ((4 * ({0,+,1}<nuw><nsw><%for.cond> /u 2))<nuw><nsw> + %storage)<nsw> U: [0,-3) S: [-9223372036854775808,9223372036854775805) Exits: ((4 * ((zext i32 %width to i64) /u 2))<nuw><nsw> + %storage)<nsw> LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> ((4 * (sext i32 %rem to i64))<nsw> + %storage)<nsw> U: [0,-3) S: [-9223372036854775808,9223372036854775805) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %1 = load i32, i32* %arrayidx, align 4
 ; CHECK-NEXT:    --> %1 U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %call = call i32 @_Z3adji(i32 %1)

diff  --git a/llvm/test/Analysis/ScalarEvolution/srem.ll b/llvm/test/Analysis/ScalarEvolution/srem.ll
index 6debab34e3b3..365b40d88e24 100644
--- a/llvm/test/Analysis/ScalarEvolution/srem.ll
+++ b/llvm/test/Analysis/ScalarEvolution/srem.ll
@@ -14,11 +14,11 @@ define dso_local void @_Z4loopi(i32 %width) local_unnamed_addr #0 {
 ; CHECK-NEXT:    %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
 ; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%for.cond> U: [0,-2147483648) S: [0,-2147483648) Exits: %width LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %rem = srem i32 %i.0, 2
-; CHECK-NEXT:    --> (zext i1 {false,+,true}<%for.cond> to i32) U: [0,2) S: [0,2) Exits: (zext i1 (trunc i32 %width to i1) to i32) LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> %rem U: [0,2) S: [-2,2) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %idxprom = sext i32 %rem to i64
-; CHECK-NEXT:    --> (zext i1 {false,+,true}<%for.cond> to i64) U: [0,2) S: [0,2) Exits: (zext i1 (trunc i32 %width to i1) to i64) LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> (sext i32 %rem to i64) U: [0,2) S: [-2,2) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %arrayidx = getelementptr inbounds [2 x i32], [2 x i32]* %storage, i64 0, i64 %idxprom
-; CHECK-NEXT:    --> ((4 * (zext i1 {false,+,true}<%for.cond> to i64))<nuw><nsw> + %storage)<nsw> U: [0,-3) S: [-9223372036854775808,9223372036854775805) Exits: ((4 * (zext i1 (trunc i32 %width to i1) to i64))<nuw><nsw> + %storage)<nsw> LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> ((4 * (sext i32 %rem to i64))<nuw><nsw> + %storage)<nsw> U: [0,-3) S: [-9223372036854775808,9223372036854775805) Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %1 = load i32, i32* %arrayidx, align 4
 ; CHECK-NEXT:    --> %1 U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %call = call i32 @_Z3adji(i32 %1)


        


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