6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-03-15 07:33:18 +00:00
Code Issues Projects Releases Wiki Activity

Corruptly merge constants with explicit and implicit alignments.

Browse Source 
Constant merge can merge a constant with implicit alignment with one that has
explicit alignment. Before this change it was assuming that the explicit
alignment was higher than the implicit one, causing the result to be under
aligned in some cases.

Fixes pr17815.

Patch by Chris Smowton!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194506 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2013-11-12 20:21:43 +00:00
parent 72c84a8294
commit 46456f6a2f
2 changed files with 35 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
lib/Transforms/IPO/ConstantMerge.cpp
View File

@ -93,9 +93,12 @@ bool ConstantMerge::hasKnownAlignment(GlobalVariable *GV) const {
}
unsigned ConstantMerge::getAlignment(GlobalVariable *GV) const {
unsigned Align = GV->getAlignment();
if (Align)
return Align;
if (TD)
return TD->getPreferredAlignment(GV);
return GV->getAlignment();
return 0;
}
bool ConstantMerge::runOnModule(Module &M) {
@ -210,9 +213,9 @@ bool ConstantMerge::runOnModule(Module &M) {
// Bump the alignment if necessary.
if (Replacements[i].first->getAlignment() ||
Replacements[i].second->getAlignment()) {
Replacements[i].second->setAlignment(std::max(
Replacements[i].first->getAlignment(),
Replacements[i].second->getAlignment()));
Replacements[i].second->setAlignment(
std::max(getAlignment(Replacements[i].first),
getAlignment(Replacements[i].second)));
}
// Eliminate any uses of the dead global.

28
test/Transforms/ConstantMerge/align.ll Normal file
View File

@ -0,0 +1,28 @@
; RUN: opt -constmerge -S < %s | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
; Test that with a TD we do merge and mark the alignment as 4
@T1A = internal unnamed_addr constant i32 1
@T1B = internal unnamed_addr constant i32 1, align 2
; CHECK: @T1B = internal unnamed_addr constant i32 1, align 4
define void @test1(i32** %P1, i32** %P2) {
store i32* @T1A, i32** %P1
store i32* @T1B, i32** %P2
ret void
}
; Test that even with a TD we set the alignment to the maximum if both constants
; have explicit alignments.
@T2A = internal unnamed_addr constant i32 2, align 1
@T2B = internal unnamed_addr constant i32 2, align 2
; CHECK: @T2B = internal unnamed_addr constant i32 2, align 2
define void @test2(i32** %P1, i32** %P2) {
store i32* @T2A, i32** %P1
store i32* @T2B, i32** %P2
ret void
}