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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-06-29 18:51:03 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-10-23 17:44:52 +0200 |
| commit | 5c5dc0a95fd65a7fbbb05ba9f018bc8dfebaa97d (patch) | |
| tree | 3a0377160c9cfb8ea232b6d8370f65e600e08f9d /simplify.c | |
| parent | a80921db90cd8de52b2fa37bf61e6156dd3a6bcd (diff) | |
| download | sparse-dev-5c5dc0a95fd65a7fbbb05ba9f018bc8dfebaa97d.tar.gz | |
canonicalize unsigned compares against 0 or 1
Some unsigned compares against 0 or 1 are equivalent to testing
equality with 0 (x <= 0, x > 0, x < 1, x >= 1).
Canonicalize them to this later, more common form.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'simplify.c')
| -rw-r--r-- | simplify.c | 20 |
1 files changed, 20 insertions, 0 deletions
@@ -1176,11 +1176,31 @@ static int simplify_constant_rightside(struct instruction *insn) case OP_SET_B: if (!value) { // (x < 0) --> 0 return replace_with_pseudo(insn, value_pseudo(0)); + } else if (value == 1) { // (x < 1) --> (x == 0) + insn->src2 = value_pseudo(0); + insn->opcode = OP_SET_EQ; + return REPEAT_CSE; } break; case OP_SET_AE: if (!value) { // (x >= 0) --> 1 return replace_with_pseudo(insn, value_pseudo(1)); + } else if (value == 1) { // (x >= 1) --> (x != 0) + insn->src2 = value_pseudo(0); + insn->opcode = OP_SET_NE; + return REPEAT_CSE; + } + break; + case OP_SET_BE: + if (!value) { // (x <= 0) --> (x == 0) + insn->opcode = OP_SET_EQ; + return REPEAT_CSE; + } + break; + case OP_SET_A: + if (!value) { // (x > 0) --> (x != 0) + insn->opcode = OP_SET_NE; + return REPEAT_CSE; } break; } |