From: Andrew Pinski <apin...@marvell.com>
Currently we fold (type) X op CST into (type) (X op ((type-x) CST)) when the
conversion widens
but not when the conversion is a nop. For the same reason why we move the
widening conversion
(the possibility of removing an extra conversion), we should do the same if the
conversion is a
nop.
Committed as approved with the comment change.
PR tree-optimization/103228
PR tree-optimization/55177
gcc/ChangeLog:
* match.pd ((type) X bitop CST): Also do this
transformation for nop conversions.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr103228-1.c: New test.
* gcc.dg/tree-ssa/pr55177-1.c: New test.
---
gcc/match.pd | 6 ++++--
gcc/testsuite/gcc.dg/tree-ssa/pr103228-1.c | 11 +++++++++++
gcc/testsuite/gcc.dg/tree-ssa/pr55177-1.c | 14 ++++++++++++++
3 files changed, 29 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr103228-1.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr55177-1.c
diff --git a/gcc/match.pd b/gcc/match.pd
index cd8f349f618..4dc66fb47f2 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1616,8 +1616,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
Restrict it to GIMPLE to avoid endless recursions. */
&& (bitop != BIT_AND_EXPR || GIMPLE)
&& (/* That's a good idea if the conversion widens the operand, thus
- after hoisting the conversion the operation will be narrower. */
- TYPE_PRECISION (TREE_TYPE (@0)) < TYPE_PRECISION (type)
+ after hoisting the conversion the operation will be narrower.
+ It is also a good if the conversion is a nop as moves the
+ conversion to one side; allowing for combining of the
conversions. */
+ TYPE_PRECISION (TREE_TYPE (@0)) <= TYPE_PRECISION (type)
/* It's also a good idea if the conversion is to a non-integer
mode. */
|| GET_MODE_CLASS (TYPE_MODE (type)) != MODE_INT
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr103228-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr103228-1.c
new file mode 100644
index 00000000000..a7539819cf2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr103228-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+int f(int a, int b)
+{
+ b|=1u;
+ b|=2;
+ return b;
+}
+/* { dg-final { scan-tree-dump-times "\\\| 3" 1 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "\\\| 1" 0 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "\\\| 2" 0 "optimized"} } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr55177-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr55177-1.c
new file mode 100644
index 00000000000..de1a264345c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr55177-1.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+extern int x;
+
+void foo(void)
+{
+ int a = __builtin_bswap32(x);
+ a &= 0x5a5b5c5d;
+ x = __builtin_bswap32(a);
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_bswap32" 0 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "& 1566333786" 1 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "& 1515936861" 0 "optimized"} } */
--
2.17.1
