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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2016-12-18 18:26:02 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-10-20 22:35:43 +0200 |
| commit | 0c8f2a719d30a42945f4dbcce4b2f906defad2d2 (patch) | |
| tree | 98a75ab3ca75881e980d4423afec1481eb7b5673 /simplify.c | |
| parent | d0329076fd9e0228f9586e21406ab2a4babb5c4d (diff) | |
| download | sparse-dev-0c8f2a719d30a42945f4dbcce4b2f906defad2d2.tar.gz | |
sub: simplify (x - -y) --> (x + y)
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'simplify.c')
| -rw-r--r-- | simplify.c | 16 |
1 files changed, 15 insertions, 1 deletions
@@ -1358,6 +1358,20 @@ static int simplify_associative_binop(struct instruction *insn) return REPEAT_CSE; } +static int simplify_sub(struct instruction *insn) +{ + pseudo_t src2 = insn->src2; + struct instruction *def; + + switch (DEF_OPCODE(def, src2)) { + case OP_NEG: // (x - -y) --> (x + y) + insn->opcode = OP_ADD; + return replace_pseudo(insn, &insn->src2, def->src); + } + + return 0; +} + static int simplify_constant_unop(struct instruction *insn) { long long val = insn->src1->value; @@ -1818,8 +1832,8 @@ int simplify_instruction(struct instruction *insn) } switch (insn->opcode) { + case OP_SUB: return simplify_sub(insn); case OP_ADD: - case OP_SUB: case OP_MUL: case OP_AND: case OP_OR: |