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 | 2 ++
validation/optim/muldiv-minus-one.c | 5 +++++
2 files changed, 7 insertions(+)
diff --git a/simplify.c b/simplify.c
index 363cc5ad7..86d2f5da9 100644
--- a/simplify.c
+++ b/simplify.c
@@ -323,6 +323,8 @@ static int simplify_mul_div(struct instruction *insn, long long value)
case OP_MULU:
if (value == 0)
return replace_with_pseudo(insn, insn->src2);
+ /* Fall through */
+ case OP_DIVS:
if (!(value & sbit)) // positive
break;
diff --git a/validation/optim/muldiv-minus-one.c b/validation/optim/muldiv-minus-one.c
index 729b73443..42b086afd 100644
--- a/validation/optim/muldiv-minus-one.c
+++ b/validation/optim/muldiv-minus-one.c
@@ -2,6 +2,8 @@ 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; }
+u32 udivm1(u32 a) { return a / (u32) -1; }
/*
* check-name: muldiv-minus-one
@@ -9,5 +11,8 @@ u32 umulm1(u32 a) { return a * (u32) -1; }
* check-output-ignore
*
* check-output-excludes: mul[us]\\.
+ * check-output-excludes: divs\\.
* check-output-contains: neg\\.
+ * check-output-contains: divu\\.
+ * check-output-pattern-3-times: neg\\.
*/
--
2.11.0
--
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