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author | Bob Wilson <bob.wilson@apple.com> | 2013-11-15 19:09:27 +0000 |
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committer | Bob Wilson <bob.wilson@apple.com> | 2013-11-15 19:09:27 +0000 |
commit | cc7052343e5e955d4e2f48885c06360f9003390a (patch) | |
tree | 8832fd14ebae789ee88bab5009cc33fbc89e3ec7 /lib/Target/X86 | |
parent | 5cddda6d13ab66c462ccbd61255ad6e6f95e9f6f (diff) | |
download | llvm-cc7052343e5e955d4e2f48885c06360f9003390a.tar.gz llvm-cc7052343e5e955d4e2f48885c06360f9003390a.tar.bz2 llvm-cc7052343e5e955d4e2f48885c06360f9003390a.tar.xz |
Avoid illegal integer promotion in fastisel
Stop folding constant adds into GEP when the type size doesn't match.
Otherwise, the adds' operands are effectively being promoted, changing the
conditions of an overflow. Results are different when:
sext(a) + sext(b) != sext(a + b)
Problem originally found on x86-64, but also fixed issues with ARM and PPC,
which used similar code.
<rdar://problem/15292280>
Patch by Duncan Exon Smith!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194840 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86')
-rw-r--r-- | lib/Target/X86/X86FastISel.cpp | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp index 928dea91b4..97f96ab72c 100644 --- a/lib/Target/X86/X86FastISel.cpp +++ b/lib/Target/X86/X86FastISel.cpp @@ -561,13 +561,8 @@ redo_gep: Disp += CI->getSExtValue() * S; break; } - if (isa<AddOperator>(Op) && - (!isa<Instruction>(Op) || - FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()] - == FuncInfo.MBB) && - isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) { - // An add (in the same block) with a constant operand. Fold the - // constant. + if (canFoldAddIntoGEP(U, Op)) { + // A compatible add with a constant operand. Fold the constant. ConstantInt *CI = cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1)); Disp += CI->getSExtValue() * S; |