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| author | David Majnemer <david.majnemer@gmail.com> | 2015-05-22 23:02:11 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2015-05-22 23:02:11 +0000 |
| commit | 4c3753c4d483f8115df78507117a105438b42ec9 (patch) | |
| tree | 0ab5abf1241e0f189dd74055eadecb47a40ffd2a /clang/lib/Frontend/CompilerInvocation.cpp | |
| parent | 25f82aae57d2ce48ad9cff8cb34a6c3dc10ad519 (diff) | |
| download | llvm-4c3753c4d483f8115df78507117a105438b42ec9.zip llvm-4c3753c4d483f8115df78507117a105438b42ec9.tar.gz llvm-4c3753c4d483f8115df78507117a105438b42ec9.tar.bz2 | |
[InstCombine] Don't eagerly propagate nsw for A*B+A*C => A*(B+C)
InstCombine transforms A *nsw B +nsw A *nsw C to A *nsw (B + C).
This is incorrect -- e.g. if A = -1, B = 1, C = INT_SMAX. Then
nothing in the LHS overflows, but the multiplication in RHS overflows.
We need to first make sure that we won't multiple by INT_SMAX + 1.
Test case `add_of_mul` contributed by Sanjoy Das.
This fixes PR23635.
Differential Revision: http://reviews.llvm.org/D9629
llvm-svn: 238066
Diffstat (limited to 'clang/lib/Frontend/CompilerInvocation.cpp')
0 files changed, 0 insertions, 0 deletions