This makes sure to use a VIEW_CONVERT_EXPR for converting
vector signedness in the -((int)x >> (prec - 1)) to (unsigned)x >> (prec - 1)
simplification.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-11-30 Richard Biener <rguent...@suse.de>
PR middle-end/103485
* match.pd (-((int)x >> (prec - 1)) to (unsigned)x >> (prec - 1)):
Use VIEW_CONVERT_EXPR for vectors.
* gcc.dg/pr103485.c: New testcase.
---
gcc/match.pd | 4 +++-
gcc/testsuite/gcc.dg/pr103485.c | 10 ++++++++++
2 files changed, 13 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr103485.c
diff --git a/gcc/match.pd b/gcc/match.pd
index e14f97ee1cd..d467a1c4e45 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1611,7 +1611,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(with { tree stype = TREE_TYPE (@0);
tree ntype = TYPE_UNSIGNED (stype) ? signed_type_for (stype)
: unsigned_type_for (stype); }
- (convert (rshift:ntype (convert:ntype @0) @1)))))
+ (if (VECTOR_TYPE_P (type))
+ (view_convert (rshift (view_convert:ntype @0) @1))
+ (convert (rshift (convert:ntype @0) @1))))))
/* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
when profitable.
diff --git a/gcc/testsuite/gcc.dg/pr103485.c b/gcc/testsuite/gcc.dg/pr103485.c
new file mode 100644
index 00000000000..1afa9286924
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103485.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+int foo_v256u128_0;
+unsigned __attribute__((__vector_size__ (sizeof(unsigned) * 8))) foo_v256u8_0;
+
+void
+foo (void)
+{
+ foo_v256u8_0 -= (foo_v256u8_0 >> sizeof (foo_v256u8_0) - 1) + foo_v256u128_0;
+}
--
2.31.1
