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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-10-26 07:07:06 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-11-08 02:14:14 +0100 |
| commit | 89b98b682930e5d4efe97f0ba3b412c23c6721e3 (patch) | |
| tree | 1230899350368704b9af37d23b4cf9537a9f483f | |
| parent | 36329f5318dc9a7017207e93445ac9100904183f (diff) | |
| download | sparse-89b98b682930e5d4efe97f0ba3b412c23c6721e3.tar.gz | |
cmp: simplify zext(x) cmp C --> x cmp C
When doing a compare of a zero-extended value against a constant,
this extension can be dropped and the comparison done on the
original type if the constant is within the original range and
signed compares become the corresponding unsigned one.
Simplify away these sign-extensions.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 11 | ||||
| -rw-r--r-- | validation/optim/cmp-zext-uimm1.c | 1 | ||||
| -rw-r--r-- | validation/optim/cmp-zext.c | 1 | ||||
| -rw-r--r-- | validation/optim/zext-cmpu.c | 1 |
4 files changed, 11 insertions, 3 deletions
@@ -1149,6 +1149,17 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_pseudo(insn, &insn->src1, def->src); } break; + case OP_ZEXT: + osize = def->orig_type->bit_size; + bits = bits_mask(osize); + if (value <= bits) { + const struct opcode_table *op = &opcode_table[insn->opcode]; + if (op->flags & OPF_SIGNED) + insn->opcode = op->sign; + insn->itype = def->orig_type; + return replace_pseudo(insn, &insn->src1, def->src); + } + break; } return changed; } diff --git a/validation/optim/cmp-zext-uimm1.c b/validation/optim/cmp-zext-uimm1.c index ffcdaad5..c21780ea 100644 --- a/validation/optim/cmp-zext-uimm1.c +++ b/validation/optim/cmp-zext-uimm1.c @@ -9,7 +9,6 @@ int zext_gt_p(unsigned int x) { return (zext(x) > (BITS )) == 0; } /* * check-name: cmp-zext-uimm1 * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 diff --git a/validation/optim/cmp-zext.c b/validation/optim/cmp-zext.c index ecee6b5e..ac484780 100644 --- a/validation/optim/cmp-zext.c +++ b/validation/optim/cmp-zext.c @@ -11,7 +11,6 @@ _Bool cmpu_zext(ARGS(UINT32)) { return TEST(UINT64, UINT32, a, < , 0xffffffff); /* * check-name: cmp-zext * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 diff --git a/validation/optim/zext-cmpu.c b/validation/optim/zext-cmpu.c index 279ed70e..9758e071 100644 --- a/validation/optim/zext-cmpu.c +++ b/validation/optim/zext-cmpu.c @@ -10,7 +10,6 @@ int gtl(unsigned x) { return (((long long)x) > 0x0fffffffeULL) == (x > 0xfffff /* * check-name: zext-cmpu * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 |