The following avoids ping-pong between the match.pd pattern changing
(sizetype) ((a_9 + 1) * 48) to (sizetype)(a_9 + 1) * 48 and
extract_muldiv performing the reverse transform by restricting the
match.pd pattern to narrowing conversions as the comment indicates.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR middle-end/106630
* match.pd ((T)(x * CST) -> (T)x * CST): Restrict to
narrowing conversions.
* gcc.dg/torture/pr106630.c: New testcase.
---
gcc/match.pd | 2 +-
gcc/testsuite/gcc.dg/torture/pr106630.c | 13 +++++++++++++
2 files changed, 14 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr106630.c
diff --git a/gcc/match.pd b/gcc/match.pd
index e32bda64e64..07d0a61fc3a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1917,7 +1917,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(convert (mult@0 zero_one_valued_p@1 INTEGER_CST@2))
(if (INTEGRAL_TYPE_P (type)
&& INTEGRAL_TYPE_P (TREE_TYPE (@0))
- && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (@0)))
+ && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@0)))
(mult (convert @1) (convert @2))))
/* (X << C) != 0 can be simplified to X, when C is zero_one_valued_p.
diff --git a/gcc/testsuite/gcc.dg/torture/pr106630.c
b/gcc/testsuite/gcc.dg/torture/pr106630.c
new file mode 100644
index 00000000000..d608b9151be
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr106630.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+short d, e;
+int f;
+extern short g[][24];
+char c;
+void h() {
+ char a = 6;
+ c = a;
+ for (unsigned long a = (d || e) - 1; a < c; a += f)
+ for (signed b = 0; b < 24; b++)
+ g[a][b] = 4;
+}
--
2.35.3
