[gcc r13-722] tree-optimization/105629 - spaceship recognition regression

[gcc r13-722] tree-optimization/105629 - spaceship recognition regression

[Richard Biener]

https://gcc.gnu.org/g:d918faea1217596877a35c4946500399731fbbd3

commit r13-722-gd918faea1217596877a35c4946500399731fbbd3
Author: Richard Biener <rguenther@suse.de>
Date:   Mon May 23 11:41:50 2022 +0200

    tree-optimization/105629 - spaceship recognition regression
    
    With the extra GENERIC folding we now do to
    (unsigned int) __v._M_value & 1 != (unsigned int) __v._M_value
    we end up with a sign-extending conversion to unsigned int
    rather than the sign-conversion to unsigned char we expect.
    Relaxing that fixes the regression.
    
    2022-05-23  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/105629
            * tree-ssa-phiopt.cc (spaceship_replacement): Allow
            a sign-extending conversion.

Diff:
---
 gcc/tree-ssa-phiopt.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
index 8c9c46d41f1..e61d9736937 100644
--- a/gcc/tree-ssa-phiopt.cc
+++ b/gcc/tree-ssa-phiopt.cc
@@ -2217,7 +2217,7 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
 
       if (!TYPE_UNSIGNED (ty2) || !INTEGRAL_TYPE_P (ty2))
 	return false;
-      if (TYPE_PRECISION (ty1) != TYPE_PRECISION (ty2))
+      if (TYPE_PRECISION (ty1) > TYPE_PRECISION (ty2))
 	return false;
       if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig_use_lhs))
 	return false;