https://gcc.gnu.org/g:6aff7ebb20085661a9f4ca7a4156188d63bfe7eb
commit 6aff7ebb20085661a9f4ca7a4156188d63bfe7eb
Author: Michael Meissner <meiss...@linux.ibm.com>
Date: Thu May 22 16:40:42 2025 -0400
Disable fp cmove on power9
2025-05-22 Michael Meissner <meiss...@linux.ibm.com>
gcc/
PR target/118541
* config/rs6000/rs6000.cc (have_compare_and_set_mask): Disable
unless
NaNs are disabled.
Diff:
---
gcc/config/rs6000/rs6000.cc | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 11dfde7f288b..a8a0e153c362 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -16509,11 +16509,17 @@ rs6000_maybe_emit_fp_cmove (rtx dest, rtx op, rtx
true_cond, rtx false_cond)
/* Helper function to return true if the target has instructions to do a
compare and set mask instruction that can be used with XXSEL to implement a
conditional move. It is also assumed that such a target also supports the
- "C" minimum and maximum instructions. */
+ "C" minimum and maximum instructions.
+
+ However, these instructions will trap if given a signaling NaN, so we can
+ only use them if NaNs are not expected. */
static bool
have_compare_and_set_mask (machine_mode mode)
{
+ if (!flag_finite_math_only)
+ return false;
+
switch (mode)
{
case E_SFmode:
