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[PATCH] rs6000: Don't align tiny loops to 32 bytes for POWER9
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: gcc-patches at gcc dot gnu dot org
- Cc: dje dot gcc at gmail dot com, Segher Boessenkool <segher at kernel dot crashing dot org>
- Date: Mon, 5 Mar 2018 19:10:46 +0000
- Subject: [PATCH] rs6000: Don't align tiny loops to 32 bytes for POWER9
- Authentication-results: sourceware.org; auth=none
For POWER4..POWER8 we align loops of 5..8 instructions to 32 bytes
(instead of to 16 bytes) because that executes faster. This is no
longer the case on POWER9, so we can just as well only align to 16
bytes.
Bootstrapped and tested on a p9 powerpc64le-linux. Committing to trunk.
Segher
2018-03-05 Segher Boessenkool <segher@kernel.crashing.org>
* config/rs6000/rs6000.c (rs6000_loop_align): Don't align tiny loops
to 32 bytes when compiling for POWER9.
---
gcc/config/rs6000/rs6000.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index dbc1d79..5cc116f 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -5285,8 +5285,7 @@ rs6000_loop_align (rtx label)
|| rs6000_tune == PROCESSOR_POWER5
|| rs6000_tune == PROCESSOR_POWER6
|| rs6000_tune == PROCESSOR_POWER7
- || rs6000_tune == PROCESSOR_POWER8
- || rs6000_tune == PROCESSOR_POWER9))
+ || rs6000_tune == PROCESSOR_POWER8))
return 5;
else
return align_loops_log;
--
1.8.3.1