diff options
| author | Roger Sayle <roger@nextmovesoftware.com> | 2021-08-23 12:44:37 +0100 |
|---|---|---|
| committer | Roger Sayle <roger@nextmovesoftware.com> | 2021-08-23 12:44:37 +0100 |
| commit | e7721590e08e6d87adc879f8d549557cbe2bb7bb (patch) | |
| tree | e07bef1270a6c92bb4bfff28434b3431e4945414 /gcc/fortran/openmp.c | |
| parent | 7e5f9ead16d7514b3baa0254084de94f0bfcd216 (diff) | |
| download | gcc-e7721590e08e6d87adc879f8d549557cbe2bb7bb.zip gcc-e7721590e08e6d87adc879f8d549557cbe2bb7bb.tar.gz gcc-e7721590e08e6d87adc879f8d549557cbe2bb7bb.tar.bz2 | |
Improved handling of division/modulus in bit CCP.
This patch implements support for TRUNC_MOD_EXPR and TRUNC_DIV_EXPR
in tree-ssa's bit CCP pass. This is mostly for completeness, as the
VRP pass already provides better bounds for these operations, but
seeing mask values of all_ones in my debugging/instrumentation logs
seemed overly pessimistic. With this patch, the expression X%10
has a nonzero bits of 0x0f (for unsigned X), likewise (X&1)/3 has
a known value of zero, and (X&3)/3 has a nonzero bits mask of 0x1.
2021-08-23 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
* tree-ssa-ccp.c (bit_value_binop) [TRUNC_MOD_EXPR, TRUNC_DIV_EXPR]:
Provide bounds for unsigned (and signed with non-negative operands)
division and modulus.
Diffstat (limited to 'gcc/fortran/openmp.c')
0 files changed, 0 insertions, 0 deletions