[llvm] 49143f9 - [IndVars] Forget the SCEV when the instruction has been sunk.

[via llvm-commits]

Author: luxufan
Date: 2022-11-06T22:46:49+08:00
New Revision: 49143f9d1471e3f01a6d32001676b29274298e22

URL: https://github.com/llvm/llvm-project/commit/49143f9d1471e3f01a6d32001676b29274298e22
DIFF: https://github.com/llvm/llvm-project/commit/49143f9d1471e3f01a6d32001676b29274298e22.diff

LOG: [IndVars] Forget the SCEV when the instruction has been sunk.

In the past, the SCEV expression of the sunk instruction was not
forgetted. This led to the incorrect block dispositions after the
instruction be sunk.

Fixes https://github.com/llvm/llvm-project/issues/58662

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D137060

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
    llvm/test/Transforms/IndVarSimplify/scev-invalidation.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index f6431b77d8027..fdc1232ad4fa6 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1281,7 +1281,7 @@ bool IndVarSimplify::sinkUnusedInvariants(Loop *L) {
 
     MadeAnyChanges = true;
     ToMove->moveBefore(*ExitBlock, InsertPt);
-    SE->forgetBlockAndLoopDispositions(ToMove);
+    SE->forgetValue(ToMove);
     if (Done) break;
     InsertPt = ToMove->getIterator();
   }

diff  --git a/llvm/test/Transforms/IndVarSimplify/scev-invalidation.ll b/llvm/test/Transforms/IndVarSimplify/scev-invalidation.ll
index 0dac4f3eb13a0..5cecdac7d99f4 100644
--- a/llvm/test/Transforms/IndVarSimplify/scev-invalidation.ll
+++ b/llvm/test/Transforms/IndVarSimplify/scev-invalidation.ll
@@ -70,3 +70,57 @@ exit:
   %res = add i32 %c.ext, %or
   ret i32 %res
 }
+
+define i8 @l(i32 %inc, i1 %tobool.not.i) {
+; CHECK-LABEL: @l(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer.header:
+; CHECK-NEXT:    br label [[INNER:%.*]]
+; CHECK:       inner:
+; CHECK-NEXT:    [[C_05_I:%.*]] = phi i32 [ [[INC_I:%.*]], [[INNER]] ], [ 0, [[OUTER_HEADER]] ]
+; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[C_05_I]], 1
+; CHECK-NEXT:    [[CMP_I:%.*]] = icmp ugt i32 [[C_05_I]], 0
+; CHECK-NEXT:    [[OR_COND_I:%.*]] = select i1 [[CMP_I]], i1 true, i1 [[TOBOOL_NOT_I:%.*]]
+; CHECK-NEXT:    br i1 [[OR_COND_I]], label [[OUTER_LATCH:%.*]], label [[INNER]]
+; CHECK:       outer.latch:
+; CHECK-NEXT:    [[C_05_I_LCSSA:%.*]] = phi i32 [ [[C_05_I]], [[INNER]] ]
+; CHECK-NEXT:    [[LCSSA:%.*]] = phi i32 [ 0, [[INNER]] ]
+; CHECK-NEXT:    [[AND:%.*]] = and i32 1, [[INC:%.*]]
+; CHECK-NEXT:    [[TMP0:%.*]] = trunc i32 [[AND]] to i8
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C_05_I_LCSSA]] to i8
+; CHECK-NEXT:    [[TMP2:%.*]] = sub i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i8 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[OUTER_HEADER]], label [[IF_THEN:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    ret i8 0
+;
+entry:
+  br label %outer.header
+
+outer.header:                                         ; preds = %h.exit, %entry
+  %outer.iv = phi i16 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
+  %and = and i32 1, %inc
+  %conv = sext i16 %outer.iv to i32
+  br label %inner
+
+inner:                                     ; preds = %while.body.i, %for.cond
+  %c.05.i = phi i32 [ %inc.i, %inner ], [ 0, %outer.header ]
+  %i.addr.04.i = phi i32 [ 0, %inner ], [ %conv, %outer.header ]
+  %inc.i = add nsw i32 %c.05.i, 1
+  %cmp.i = icmp sgt i32 %c.05.i, 0
+  %or.cond.i = select i1 %cmp.i, i1 true, i1 %tobool.not.i
+  br i1 %or.cond.i, label %outer.latch, label %inner
+
+outer.latch:                                           ; preds = %while.body.i
+  %lcssa = phi i32 [ 0, %inner ]
+  %0 = trunc i32 %and to i8
+  %1 = trunc i32 %c.05.i to i8
+  %2 = sub i8 %0, %1
+  %tobool.not = icmp eq i8 %2, 0
+  %outer.iv.next = add i16 %outer.iv, 1
+  br i1 %tobool.not, label %outer.header, label %if.then
+
+if.then:                                          ; preds = %h.exit
+  ret i8 0
+}