6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-28 09:31:03 +00:00
Code Issues Projects Releases Wiki Activity

Transforms: Don't create bad weights when eliminating dead cases

Browse Source 
If we happen to eliminate every case in a switch that has branch
weights, we currently try to create metadata for the one remaining
branch, triggering an assert. Instead, we need to check that the
metadata we're trying to create is sensible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197791 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Justin Bogner 2013-12-20 08:21:30 +00:00
parent 35c913b5b1
commit bcb726dc8a
2 changed files with 26 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/Transforms/Utils/SimplifyCFG.cpp
View File

@ -3222,7 +3222,7 @@ static bool EliminateDeadSwitchCases(SwitchInst *SI) {
Case.getCaseSuccessor()->removePredecessor(SI->getParent());
SI->removeCase(Case);
}
if (HasWeight) {
if (HasWeight && Weights.size() >= 2) {
SmallVector<uint32_t, 8> MDWeights(Weights.begin(), Weights.end());
SI->setMetadata(LLVMContext::MD_prof,
MDBuilder(SI->getParent()->getContext()).

25
test/Transforms/SimplifyCFG/preserve-branchweights.ll
View File

@ -313,6 +313,31 @@ sw.epilog:
ret void
}
;; If every case is dead, make sure they are all removed. This used to
;; crash trying to merge the metadata.
define void @test13(i32 %x) nounwind {
entry:
%i = shl i32 %x, 1
switch i32 %i, label %a [
i32 21, label %b
i32 25, label %c
], !prof !8
; CHECK-LABEL: @test13(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @helper
; CHECK-NEXT: ret void
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
c:
call void @helper(i32 2) nounwind
ret void
}
!0 = metadata !{metadata !"branch_weights", i32 3, i32 5}
!1 = metadata !{metadata !"branch_weights", i32 1, i32 1}
!2 = metadata !{metadata !"branch_weights", i32 1, i32 2}