[gcc r14-10114] rs6000: Use bcdsub. instead of bcdadd. for bcd invalid number checking

[gcc r14-10114] rs6000: Use bcdsub. instead of bcdadd. for bcd invalid number checking

[HaoChen Gui]

https://gcc.gnu.org/g:09680e3ee7d72978b493dd4127ce2e769f96a45e

commit r14-10114-g09680e3ee7d72978b493dd4127ce2e769f96a45e
Author: Haochen Gui <guihaoc@gcc.gnu.org>
Date:   Thu Apr 25 09:55:53 2024 +0800

    rs6000: Use bcdsub. instead of bcdadd. for bcd invalid number checking
    
    bcdadd. might causes overflow which also set the overflow/invalid bit.
    bcdsub. doesn't have the issue when do subtracting on two same bcd number.
    
    gcc/
            * config/rs6000/altivec.md (*bcdinvalid_<mode>): Replace bcdadd
            with bcdsub.
            (bcdinvalid_<mode>): Likewise.
    
    gcc/testsuite/
            * gcc.target/powerpc/bcd-4.c: Adjust the number of bcdadd and
            bcdsub.

Diff:
---
 gcc/config/rs6000/altivec.md             | 6 +++---
 gcc/testsuite/gcc.target/powerpc/bcd-4.c | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/gcc/config/rs6000/altivec.md b/gcc/config/rs6000/altivec.md
index 4d4c94ff0a0..bb20441c096 100644
--- a/gcc/config/rs6000/altivec.md
+++ b/gcc/config/rs6000/altivec.md
@@ -4586,18 +4586,18 @@
   [(set (reg:CCFP CR6_REGNO)
 	(compare:CCFP
 	 (unspec:V2DF [(match_operand:VBCD 1 "register_operand" "v")]
-		      UNSPEC_BCDADD)
+		      UNSPEC_BCDSUB)
 	 (match_operand:V2DF 2 "zero_constant" "j")))
    (clobber (match_scratch:VBCD 0 "=v"))]
   "TARGET_P8_VECTOR"
-  "bcdadd. %0,%1,%1,0"
+  "bcdsub. %0,%1,%1,0"
   [(set_attr "type" "vecsimple")])
 
 (define_expand "bcdinvalid_<mode>"
   [(parallel [(set (reg:CCFP CR6_REGNO)
 		   (compare:CCFP
 		    (unspec:V2DF [(match_operand:VBCD 1 "register_operand")]
-				 UNSPEC_BCDADD)
+				 UNSPEC_BCDSUB)
 		    (match_dup 2)))
 	      (clobber (match_scratch:VBCD 3))])
    (set (match_operand:SI 0 "register_operand")
diff --git a/gcc/testsuite/gcc.target/powerpc/bcd-4.c b/gcc/testsuite/gcc.target/powerpc/bcd-4.c
index 2c7041c4d32..6d2c59ef792 100644
--- a/gcc/testsuite/gcc.target/powerpc/bcd-4.c
+++ b/gcc/testsuite/gcc.target/powerpc/bcd-4.c
@@ -2,8 +2,8 @@
 /* { dg-require-effective-target int128 } */
 /* { dg-require-effective-target p9vector_hw } */
 /* { dg-options "-mdejagnu-cpu=power9 -O2 -save-temps" } */
-/* { dg-final { scan-assembler-times {\mbcdadd\M} 7 } } */
-/* { dg-final { scan-assembler-times {\mbcdsub\M} 18 } } */
+/* { dg-final { scan-assembler-times {\mbcdadd\M} 5 } } */
+/* { dg-final { scan-assembler-times {\mbcdsub\M} 20 } } */
 /* { dg-final { scan-assembler-times {\mbcds\M} 2 } } */
 /* { dg-final { scan-assembler-times {\mdenbcdq\M} 1 } } */