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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2021-01-13 00:49:16 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2021-01-26 22:49:11 +0100 |
| commit | 7b1d4ca6b5ad28ccf8e489c58fe99c00b1436bfb (patch) | |
| tree | 50474efa41db1a8605b07210dd361e1618d45145 | |
| parent | 61010b15b6074fcfee4256b848b1123a57d61947 (diff) | |
| download | sparse-7b1d4ca6b5ad28ccf8e489c58fe99c00b1436bfb.tar.gz | |
cmps: canonicalize SMIN/SMAX +- 1 --> EQ/NE
Compares with SMIN + 1 or SMAX - 1 are equivalent to an equality
testing. For example, (x < SMIN + 1) is the same as (x == SMIN).
Canonicalize these to the equality testing since these are usually
simpler to handle.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 8 | ||||
| -rw-r--r-- | validation/optim/canonical-cmpe-minmax.c | 1 |
2 files changed, 8 insertions, 1 deletions
@@ -1175,24 +1175,32 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_with_pseudo(insn, value_pseudo(0)); if (value == sign_mask(size)) // (x < SMAX) --> (x != SMAX) return replace_opcode(insn, OP_SET_NE); + if (value == sign_bit(size) + 1)// (x < SMIN + 1) --> (x == SMIN) + return replace_binop_value(insn, OP_SET_EQ, sign_bit(size)); break; case OP_SET_LE: if (value == sign_mask(size)) // (x <= SMAX) --> 1 return replace_with_pseudo(insn, value_pseudo(1)); if (value == sign_bit(size)) // (x <= SMIN) --> (x == SMIN) return replace_opcode(insn, OP_SET_EQ); + if (value == sign_mask(size) - 1) // (x <= SMAX - 1) --> (x != SMAX) + return replace_binop_value(insn, OP_SET_NE, sign_mask(size)); break; case OP_SET_GE: if (value == sign_bit(size)) // (x >= SMIN) --> 1 return replace_with_pseudo(insn, value_pseudo(1)); if (value == sign_mask(size)) // (x >= SMAX) --> (x == SMAX) return replace_opcode(insn, OP_SET_EQ); + if (value == sign_bit(size) + 1)// (x >= SMIN + 1) --> (x != SMIN) + return replace_binop_value(insn, OP_SET_NE, sign_bit(size)); break; case OP_SET_GT: if (value == sign_mask(size)) // (x > SMAX) --> 0 return replace_with_pseudo(insn, value_pseudo(0)); if (value == sign_bit(size)) // (x > SMIN) --> (x != SMIN) return replace_opcode(insn, OP_SET_NE); + if (value == sign_mask(size) - 1) // (x > SMAX - 1) --> (x == SMAX) + return replace_binop_value(insn, OP_SET_EQ, sign_mask(size)); break; case OP_SET_B: diff --git a/validation/optim/canonical-cmpe-minmax.c b/validation/optim/canonical-cmpe-minmax.c index c7281924..32b27243 100644 --- a/validation/optim/canonical-cmpe-minmax.c +++ b/validation/optim/canonical-cmpe-minmax.c @@ -10,7 +10,6 @@ int ge_smin(int a) { return (a >= (SMIN + 1)) == (a != SMIN); } /* * check-name: canonical-cmpe-minmax * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 |