A previous patch added the simplification for multiply by -1
but we can do the same for the signed divide.
This patch add this simplification
Also add the corresponding test cases.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 3 ++-
validation/optim/muldiv-minus-one.c | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index 6c7c79e9..e3e5ff6e 100644
--- a/simplify.c
+++ b/simplify.c
@@ -324,6 +324,8 @@ static int simplify_mul_div(struct instruction *insn, long long value)
if (value == 0)
return replace_with_pseudo(insn, insn->src2);
+ /* Fall through */
+ case OP_DIVS:
if (!(value & sbit)) // positive
break;
@@ -333,7 +335,6 @@ static int simplify_mul_div(struct instruction *insn, long long value)
return REPEAT_CSE;
}
/* Fall through */
- case OP_DIVS:
case OP_DIVU:
break;
}
diff --git a/validation/optim/muldiv-minus-one.c b/validation/optim/muldiv-minus-one.c
index 729b7344..05a5f915 100644
--- a/validation/optim/muldiv-minus-one.c
+++ b/validation/optim/muldiv-minus-one.c
@@ -2,6 +2,7 @@ typedef unsigned int u32;
int smulm1(int a) { return a * -1; }
u32 umulm1(u32 a) { return a * (u32) -1; }
+int sdivm1(int a) { return a * -1; }
/*
* check-name: muldiv-minus-one
@@ -9,5 +10,6 @@ u32 umulm1(u32 a) { return a * (u32) -1; }
* check-output-ignore
*
* check-output-excludes: mul[us]\\.
+ * check-output-excludes: divs\\.
* check-output-contains: neg\\.
*/
--
2.10.2
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