6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-12 13:30:51 +00:00
Code Issues Projects Releases Wiki Activity

[InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr

Browse Source 
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224574 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bruno Cardoso Lopes 2014-12-19 14:23:15 +00:00
parent 6500a9867f
commit cba407d019
2 changed files with 34 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/Transforms/InstCombine/InstructionCombining.cpp
View File

@ -2115,8 +2115,10 @@ Instruction *InstCombiner::visitSwitchInst(SwitchInst &SI) {
for (SwitchInst::CaseIt i = SI.case_begin(), e = SI.case_end();
i != e; ++i) {
ConstantInt* CaseVal = i.getCaseValue();
Constant* NewCaseVal = ConstantExpr::getSub(cast<Constant>(CaseVal),
AddRHS);
Constant *LHS = LeadingKnownZeros
? ConstantExpr::getZExt(CaseVal, Cond->getType())
: ConstantExpr::getSExt(CaseVal, Cond->getType());
Constant* NewCaseVal = ConstantExpr::getSub(LHS, AddRHS);
assert(isa<ConstantInt>(NewCaseVal) &&
"Result of expression should be constant");
i.setValue(cast<ConstantInt>(NewCaseVal));

30
test/Transforms/InstCombine/narrow-switch.ll
View File

@ -91,3 +91,33 @@ return:
%retval.0 = phi i32 [ 24, %sw.default ], [ 123, %sw.bb2 ], [ 213, %sw.bb1 ], [ 231, %entry ]
ret i32 %retval.0
}
; Make sure to avoid assertion crashes and use the type before
; truncation to generate the sub constant expressions that leads
; to the recomputed condition.
;
; CHECK-LABEL: @trunc64to59
; CHECK: switch i59
; CHECK: i59 0, label
; CHECK: i59 18717182647723699, label
define void @trunc64to59(i64 %a) {
entry:
%tmp0 = and i64 %a, 15
%tmp1 = mul i64 %tmp0, -6425668444178048401
%tmp2 = add i64 %tmp1, 5170979678563097242
%tmp3 = mul i64 %tmp2, 1627972535142754813
switch i64 %tmp3, label %sw.default [
i64 847514119312061490, label %sw.bb1
i64 866231301959785189, label %sw.bb2
]
sw.bb1:
br label %sw.default
sw.bb2:
br label %sw.default
sw.default:
ret void
}