diff options
| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-10-22 01:13:02 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-11-08 02:12:10 +0100 |
| commit | 4146aecb9917aaad05c560280089e2557f113126 (patch) | |
| tree | 6114438d1e40864615903b8aa16e0b55a2eb76cf | |
| parent | c355e5ac5dce35f3d95c30cd5e2e9a5074c38437 (diff) | |
| download | sparse-4146aecb9917aaad05c560280089e2557f113126.tar.gz | |
cmp: simplify unsigned (x {<=,>} UMAX) into {1,0}
These compares are always true or false, so simplify them.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 5 | ||||
| -rw-r--r-- | validation/optim/set-uimm1.c | 1 |
2 files changed, 5 insertions, 1 deletions
@@ -1081,6 +1081,7 @@ static int simplify_seteq_setne(struct instruction *insn, long long value) static int simplify_compare_constant(struct instruction *insn, long long value) { + unsigned long long bits = bits_mask(insn->itype->bit_size); int changed = 0; switch (insn->opcode) { @@ -1103,10 +1104,14 @@ static int simplify_compare_constant(struct instruction *insn, long long value) case OP_SET_BE: if (!value) // (x <= 0) --> (x == 0) return replace_opcode(insn, OP_SET_EQ); + if (value == bits) // (x <= ~0) --> 1 + return replace_with_pseudo(insn, value_pseudo(1)); break; case OP_SET_A: if (!value) // (x > 0) --> (x != 0) return replace_opcode(insn, OP_SET_NE); + if (value == bits) // (x > ~0) --> 0 + return replace_with_pseudo(insn, value_pseudo(0)); break; } return changed; diff --git a/validation/optim/set-uimm1.c b/validation/optim/set-uimm1.c index d6928f59..aa9f54c3 100644 --- a/validation/optim/set-uimm1.c +++ b/validation/optim/set-uimm1.c @@ -4,7 +4,6 @@ static _Bool setgt_umax(unsigned int a) { return (a > ~0) == 0; } /* * check-name: set-uimm1 * check-command: test-linearize $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 |