diff options
| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-07-08 23:59:51 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-07-28 09:06:47 +0200 |
| commit | bc0f5843abbc4579a277392af8db70f7835f4b97 (patch) | |
| tree | 0bccb059e42748f2b3490a49730d7fc60909fa7c /simplify.c | |
| parent | 0df976f9a48170c617f056e61381143342d9b939 (diff) | |
| download | sparse-dev-bc0f5843abbc4579a277392af8db70f7835f4b97.tar.gz | |
simplify SET{EQ,NE}(ZEXT(x, N),{0,1})
A zero-extension has no effect on the result of a comparison with 0 or 1.
Optimize away the extension.
Note: this simplification was already done but only when the
original size was 1 but it can be done for all sizes.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'simplify.c')
| -rw-r--r-- | simplify.c | 17 |
1 files changed, 7 insertions, 10 deletions
@@ -608,16 +608,13 @@ static int simplify_seteq_setne(struct instruction *insn, long long value) return REPEAT_CSE; case OP_ZEXT: - if (def->orig_type->bit_size == 1) { - // Convert: - // zext.m %s <- (1) %a - // setne.1 %r <- %s, $0 - // into: - // setne.1 %s <- %a, $0 - // and same for setne/eq ... 0/1 - return replace_pseudo(insn, &insn->src1, def->src1); - } - break; + // Convert: + // zext.m %s <- (1) %a + // setne.1 %r <- %s, $0 + // into: + // setne.1 %s <- %a, $0 + // and same for setne/eq ... 0/1 + return replace_pseudo(insn, &insn->src1, def->src); } return 0; } |