This makes make_more_copies do what its documentation says, that is,
only make an intermediate pseudo if copying to a pseudo.
This regressed generated code quality when we didn't keep the original
notes that were on the copy, but since r265582 we do, and only allowing
pseudos now is a win. It also simplifies the code.
Committing.
Segher
2018-11-10 Segher Boessenkool <seg...@kernel.crashing.org>
* combine.c (make_more_copies): Only make an intermediate copy if the
dest of a move is a pseudo.
---
gcc/combine.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/gcc/combine.c b/gcc/combine.c
index 77eeae7..c314206 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -14990,12 +14990,11 @@ make_more_copies (void)
rtx set = single_set (insn);
if (!set)
continue;
+
rtx dest = SET_DEST (set);
- if (dest == pc_rtx)
- continue;
- /* See PR87871. */
- if (dest == frame_pointer_rtx)
- continue;
+ if (!(REG_P (dest) && !HARD_REGISTER_P (dest)))
+ continue;
+
rtx src = SET_SRC (set);
if (!(REG_P (src) && HARD_REGISTER_P (src)))
continue;
--
1.8.3.1
