Hi,
Commit r12-7687 exposed one miss optimization chance in function
rs6000_maybe_emit_maxc_minc, for now it only considers comparison
codes GE/GT/LE/LT, but it can support more variants with codes
UNLT/UNLE/UNGT/UNGE by reversing them into the equivalent ones
with GE/GT/LE/LT.
Bootstrapped and regtested on powerpc64-linux-gnu P8 and
powerpc64le-linux-gnu P9 and P10.
Is it ok for trunk?
BR,
Kewen
-----
PR target/105002
gcc/ChangeLog:
* config/rs6000/rs6000.cc (rs6000_maybe_emit_maxc_minc): Support more
comparison codes UNLT/UNLE/UNGT/UNGE.
---
gcc/config/rs6000/rs6000.cc | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 283e8306ff7..b6a2509788f 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -15872,6 +15872,13 @@ rs6000_maybe_emit_maxc_minc (rtx dest, rtx op, rtx
true_cond, rtx false_cond)
if (result_mode != compare_mode)
return false;
+ /* Canonicalize UN[GL][ET] to [LG][TE]. */
+ if (code == UNGE || code == UNGT || code == UNLE || code == UNLT)
+ {
+ code = reverse_condition_maybe_unordered (code);
+ std::swap (true_cond, false_cond);
+ }
+
if (code == GE || code == GT)
max_p = true;
else if (code == LE || code == LT)
--
2.27.0
