From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: linux-sparse@vger.kernel.org
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [PATCH 09/22] sub: reorganize handling of OP_{ADD,SUB}s with constant rightside
Date: Tue, 20 Oct 2020 23:10:08 +0200 [thread overview]
Message-ID: <20201020211021.82394-10-luc.vanoostenryck@gmail.com> (raw)
In-Reply-To: <20201020211021.82394-1-luc.vanoostenryck@gmail.com>
This is a preparatory step for more interesting changes later.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
simplify.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/simplify.c b/simplify.c
index b14f88405861..f837b003efd4 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1101,6 +1101,7 @@ static int simplify_constant_rightside(struct instruction *insn)
long long value = insn->src2->value;
long long sbit = 1ULL << (insn->size - 1);
long long bits = sbit | (sbit - 1);
+ int changed = 0;
switch (insn->opcode) {
case OP_OR:
@@ -1113,20 +1114,21 @@ static int simplify_constant_rightside(struct instruction *insn)
insn->opcode = OP_NOT;
return REPEAT_CSE;
}
- goto case_neutral_zero;
+ /* fallthrough */
+ case_neutral_zero:
+ if (!value)
+ return replace_with_pseudo(insn, insn->src1);
+ return 0;
case OP_SUB:
- if (value) {
- insn->opcode = OP_ADD;
- insn->src2 = eval_unop(OP_NEG, insn->size, insn->src2);
- return REPEAT_CSE;
- }
- /* Fall through */
+ insn->opcode = OP_ADD;
+ insn->src2 = eval_unop(OP_NEG, insn->size, insn->src2);
+ changed = REPEAT_CSE;
+ /* fallthrough */
case OP_ADD:
- case_neutral_zero:
if (!value)
return replace_with_pseudo(insn, insn->src1);
- return 0;
+ return changed;
case OP_ASR:
case OP_SHL:
case OP_LSR:
--
2.28.0
next prev parent reply other threads:[~2020-10-20 21:10 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 21:09 [PATCH 00/22] essential OP_ADD & OP_SUB simplifications Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 01/22] add testcases about " Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 02/22] let switch_pseudo() return REPEAT_CSE Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 03/22] extract eval_op() from eval_insn() Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 04/22] unop: add helper eval_unop() Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 05/22] unop: add helper replace_with_unop() Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 06/22] add a flag to identify commutative & associative ops Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 07/22] constants must be truncated to the operation's size Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 08/22] reassoc: simplify (x # C) # K --> x # eval(C # K) Luc Van Oostenryck
2020-10-20 21:10 ` Luc Van Oostenryck [this message]
2020-10-20 21:10 ` [PATCH 10/22] sub: canonicalize (0 - x) into -x Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 11/22] sub: simplify C - (y + D) --> eval(C-D) - y Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 12/22] sub: simplify C - (D - z) --> z + eval(C-D) Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 13/22] sub: simplify (C - y) + D --> eval(C+D) - y Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 14/22] sub: simplify (x - -y) --> (x + y) Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 15/22] add: simplify (x + -y) --> (x - y) Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 16/22] add: simplify (-x + y) --> (y - x) Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 17/22] sub: simplify (x + y) - x --> y Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 18/22] sub: simplify (x + y) - y --> x Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 19/22] sub: simplify x - (x + y) --> -y Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 20/22] sub: simplify x - (y + x) " Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 21/22] sub: simplify (x - y) + y --> x Luc Van Oostenryck
2020-10-20 21:10 ` [PATCH 22/22] sub: simplify x + (y - x) --> y Luc Van Oostenryck
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