diff options
| author | Rafael Espindola <rafael.espindola@gmail.com> | 2014-06-04 15:39:14 +0000 |
|---|---|---|
| committer | Rafael Espindola <rafael.espindola@gmail.com> | 2014-06-04 15:39:14 +0000 |
| commit | 04c225862491b656b3804bf54d17e7c291a129e3 (patch) | |
| tree | db372e2d98b8b08d7a1a8b8137e6582385054963 /llvm/test/Transforms/SimplifyCFG/switch-on-const-select.ll | |
| parent | 99a1f2e95bbc60349ac0296be2565158fe14f84a (diff) | |
| download | bcm5719-llvm-04c225862491b656b3804bf54d17e7c291a129e3.tar.gz bcm5719-llvm-04c225862491b656b3804bf54d17e7c291a129e3.zip | |
InstCombine: Improvement to check if signed addition overflows.
This patch implements two things:
1. If we know one number is positive and another is negative, we return true as
signed addition of two opposite signed numbers will never overflow.
2. Implemented TODO : If one of the operands only has one non-zero bit, and if
the other operand has a known-zero bit in a more significant place than it
(not including the sign bit) the ripple may go up to and fill the zero, but
won't change the sign. e.x - (x & ~4) + 1
We make sure that we are ignoring 0 at MSB.
Patch by Suyog Sarda.
llvm-svn: 210186
Diffstat (limited to 'llvm/test/Transforms/SimplifyCFG/switch-on-const-select.ll')
0 files changed, 0 insertions, 0 deletions
