From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: linux-sparse@vger.kernel.org
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [PATCH 09/10] cmps: canonicalize SEL(x {<,<=} y, a, b) --> SEL(x {>=,>} y, b, a)
Date: Tue, 26 Jan 2021 23:04:31 +0100 [thread overview]
Message-ID: <20210126220432.58265-10-luc.vanoostenryck@gmail.com> (raw)
In-Reply-To: <20210126220432.58265-1-luc.vanoostenryck@gmail.com>
Both compares and OP_SELECT are anti-symmetrical: swapping
the arguments is equivalent to inversing the condition.
As consequence, when combined, they're symmetrical:
swapping the arguments of the compare (or equivalently reversing
the direction of the compare) and swapping the operand of the
OP_SELECT is a no-op, both forms are equivalent.
So, canonicalize these to always use OP_GT or OP_GE.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
simplify.c | 7 +++++++
validation/optim/canonical-cmps-sel.c | 1 -
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index b29f5d5b2444..10cdf50dcbf1 100644
--- a/simplify.c
+++ b/simplify.c
@@ -2301,6 +2301,13 @@ static int simplify_select(struct instruction *insn)
if (src2 == def->src1 && src1 == def->src2)
return replace_with_pseudo(insn, src1); // SEL(y!=x,x,y) --> x
break;
+ case OP_SET_LE: case OP_SET_LT:
+ case OP_SET_BE: case OP_SET_B:
+ if (!one_use(cond))
+ break;
+ // SEL(x {<,<=} y, a, b) --> SEL(x {>=,>} y, b, a)
+ def->opcode = opcode_negate(def->opcode);
+ return switch_pseudo(insn, &insn->src2, insn, &insn->src3);
case OP_SEL:
if (constant(def->src2) && constant(def->src3)) {
// Is the def of the conditional another select?
diff --git a/validation/optim/canonical-cmps-sel.c b/validation/optim/canonical-cmps-sel.c
index f0a0effc7954..bba5e5c894f8 100644
--- a/validation/optim/canonical-cmps-sel.c
+++ b/validation/optim/canonical-cmps-sel.c
@@ -19,7 +19,6 @@ _Bool sel_leu(unsigned int a, unsigned int b, int x, int y)
/*
* check-name: canonical-cmps-sel
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-returns: 1
--
2.30.0
next prev parent reply other threads:[~2021-01-27 3:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 22:04 [PATCH 00/10] simplify and canonicalize signed compares Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 01/10] cmps: make clearer we're using the operands' size Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 02/10] cmps: fix simplification of sext(x) + signed compare of {SMAX,SMIN} Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 03/10] cmpu: fix canonicalization of unsigned (x {<,>=} C) --> (x {<=,>} C-1) Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 04/10] cmps: add testcases for simplification of signed compares Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 05/10] cmps: simplify signed compares with SMIN or SMAX Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 06/10] cmps: canonicalize signed compares with SMIN/SMAX Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 07/10] cmps: canonicalize SMIN/SMAX +- 1 --> EQ/NE Luc Van Oostenryck
2021-01-26 22:04 ` [PATCH 08/10] cmps: canonicalize signed compares with constant Luc Van Oostenryck
2021-01-26 22:04 ` Luc Van Oostenryck [this message]
2021-01-26 22:04 ` [PATCH 10/10] cmps: canonicalize SEL(x > 0, a, -a) --> SEL(x >= 0, a, -a) Luc Van Oostenryck
2021-04-17 17:16 ` [PATCH 00/10] simplify and canonicalize signed compares Linus Torvalds
2021-04-17 18:20 ` Luc Van Oostenryck
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