[llvm] r277332 - [SimplifyCFG] Fix nasty RAUW bug from r277325
James Molloy via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 1 02:34:48 PDT 2016
Author: jamesm
Date: Mon Aug 1 04:34:48 2016
New Revision: 277332
URL: http://llvm.org/viewvc/llvm-project?rev=277332&view=rev
Log:
[SimplifyCFG] Fix nasty RAUW bug from r277325
Using RAUW was wrong here; if we have a switch transform such as:
18 -> 6 then
6 -> 0
If we use RAUW, while performing the second transform the *transformed* 6
from the first will be also replaced, so we end up with:
18 -> 0
6 -> 0
Found by clang stage2 bootstrap; testcase added.
Modified:
llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
llvm/trunk/test/Transforms/SimplifyCFG/rangereduce.ll
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=277332&r1=277331&r2=277332&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Aug 1 04:34:48 2016
@@ -5132,11 +5132,12 @@ static bool ReduceSwitchRange(SwitchInst
Builder.CreateShl(Sub, Ty->getBitWidth() - Shift));
SI->replaceUsesOfWith(SI->getCondition(), Rot);
- for (auto &C : SI->cases()) {
+ for (SwitchInst::CaseIt C = SI->case_begin(), E = SI->case_end(); C != E;
+ ++C) {
auto *Orig = C.getCaseValue();
auto Sub = Orig->getValue() - APInt(Ty->getBitWidth(), Base);
- SI->replaceUsesOfWith(Orig,
- ConstantInt::get(Ty, Sub.lshr(ShiftC->getValue())));
+ C.setValue(
+ cast<ConstantInt>(ConstantInt::get(Ty, Sub.lshr(ShiftC->getValue()))));
}
return true;
}
Modified: llvm/trunk/test/Transforms/SimplifyCFG/rangereduce.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/rangereduce.ll?rev=277332&r1=277331&r2=277332&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/rangereduce.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/rangereduce.ll Mon Aug 1 04:34:48 2016
@@ -192,4 +192,30 @@ two:
ret i32 1143
three:
ret i32 99783
-}
\ No newline at end of file
+}
+
+; CHECK-LABEL: @test9
+; CHECK: switch
+; CHECK: i32 6
+; CHECK: i32 7
+; CHECK: i32 0
+; CHECK: i32 2
+define i32 @test9(i32 %a) {
+ switch i32 %a, label %def [
+ i32 18, label %one
+ i32 20, label %two
+ i32 6, label %three
+ i32 10, label %three
+ ]
+
+def:
+ ret i32 8867
+
+one:
+ ret i32 11984
+two:
+ ret i32 1143
+three:
+ ret i32 99783
+}
+
More information about the llvm-commits
mailing list