Since currently ranger does not work with the complexity of COND_EXPR in
some cases so delaying the simplification of `1/x` for signed types
help code generation.
tree-ssa/divide-8.c is a new testcase where this can help.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/113301
gcc/ChangeLog:
* match.pd (`1/x`): Delay signed case until late.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/divide-8.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
gcc/match.pd | 12 +++++++-----
gcc/testsuite/gcc.dg/tree-ssa/divide-8.c | 13 +++++++++++++
2 files changed, 20 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/divide-8.c
diff --git a/gcc/match.pd b/gcc/match.pd
index d75babd86c2..81a389057cf 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -560,7 +560,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
1 / X -> X >= -1 && X <= 1 ? X : 0 for signed integer X.
But not for 1 / 0 so that we can get proper warnings and errors,
and not for 1-bit integers as they are edge cases better handled
- elsewhere. */
+ elsewhere. Delay the conversion of the signed division until late
+ because `1 / X` is simplier to handle than the resulting COND_EXPR. */
(simplify
(trunc_div integer_onep@0 @1)
(if (INTEGRAL_TYPE_P (type)
@@ -569,10 +570,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& (!flag_non_call_exceptions || tree_expr_nonzero_p (@1)))
(if (TYPE_UNSIGNED (type))
(convert (eq:boolean_type_node @1 { build_one_cst (type); }))
- (with { tree utype = unsigned_type_for (type); }
- (cond (le (plus (convert:utype @1) { build_one_cst (utype); })
- { build_int_cst (utype, 2); })
- @1 { build_zero_cst (type); })))))
+ (if (!canonicalize_math_p ())
+ (with { tree utype = unsigned_type_for (type); }
+ (cond (le (plus (convert:utype @1) { build_one_cst (utype); })
+ { build_int_cst (utype, 2); })
+ @1 { build_zero_cst (type); }))))))
/* Combine two successive divisions. Note that combining ceil_div
and floor_div is trickier and combining round_div even more so. */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/divide-8.c
b/gcc/testsuite/gcc.dg/tree-ssa/divide-8.c
new file mode 100644
index 00000000000..b8149088177
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/divide-8.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized" } */
+/* PR tree-optimization/113301 */
+/* We should figure out that 1/(x+1) range is [-1,1]
+ and then /2 is always 0. */
+
+void link_error(void);
+void func(int x){
+ int c=(1/(x+1))/2;
+ if (c != 0)
+ link_error();
+}
+/* { dg-final { scan-tree-dump-not "link_error " "optimized" } } */
--
2.39.3
