6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 04:30:23 +00:00
Code Issues Projects Releases Wiki Activity

fix an off-by-one bug that caused a crash analyzing

Browse Source 
ashr's with huge shift amounts, PR8896


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122814 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-04 18:19:15 +00:00
parent ba64b9706a
commit 43b40a4620
2 changed files with 38 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/Analysis/ValueTracking.cpp
View File

@ -337,7 +337,7 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
// (ashr X, C1) & C2 == 0 iff (-1 >> C1) & C2 == 0
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
// Compute the new bits that are at the top now.
uint64_t ShiftAmt = SA->getLimitedValue(BitWidth);
uint64_t ShiftAmt = SA->getLimitedValue(BitWidth-1);
// Signed shift right.
APInt Mask2(Mask.shl(ShiftAmt));

37
test/Transforms/InstCombine/crash.ll
View File

@ -298,3 +298,40 @@ entry:
}
; PR8896
@g_54 = external global [7 x i16]
define void @test15(i32* %p_92) nounwind {
entry:
%0 = load i32* %p_92, align 4
%1 = icmp ne i32 %0, 0
%2 = zext i1 %1 to i32
%3 = call i32 @func_14() nounwind
%4 = trunc i32 %3 to i16
%5 = sext i16 %4 to i32
%6 = trunc i32 %5 to i16
br i1 undef, label %"3", label %"5"
"3": ; preds = %entry
%7 = sext i16 %6 to i32
%8 = ashr i32 %7, -1649554541
%9 = trunc i32 %8 to i16
br label %"5"
"5": ; preds = %"3", %entry
%10 = phi i16 [ %9, %"3" ], [ %6, %entry ]
%11 = sext i16 %10 to i32
%12 = xor i32 %2, %11
%13 = sext i32 %12 to i64
%14 = icmp ne i64 %13, 0
br i1 %14, label %return, label %"7"
"7": ; preds = %"5"
ret void
return: ; preds = %"5"
ret void
}
declare i32 @func_14()