[gcc r11-7695] rs6000: Workaround for PR98092

[Segher Boessenkool]

https://gcc.gnu.org/g:a0b5843a9b2b3e93bd119d5aef583f53ad2ef0bc

commit r11-7695-ga0b5843a9b2b3e93bd119d5aef583f53ad2ef0bc
Author: Segher Boessenkool <segher@kernel.crashing.org>
Date:   Tue Mar 16 18:29:11 2021 +0000

    rs6000: Workaround for PR98092
    
    The bcdinvalid_<mode> RTL instruction uses the "unordered" comparison,
    which cannot be used if we have -ffinite-math-only.  We really need
    CCMODEs that describe what bits in a CR field are set by other insns
    than just comparisons, but that is a lot more surgery, and it is stage 4
    now.  This patch does a simple workaround.
    
    2021-03-16  Segher Boessenkool  <segher@kernel.crashing.org>
    
            PR target/98092
            * config/rs6000/predicates.md (branch_comparison_operator): Allow
            ordered and unordered for CCFPmode, if flag_finite_math_only.
    
    gcc/testsuite/
            PR target/98092
            * gcc.target/powerpc/pr98092.c: New.

Diff:
---
 gcc/config/rs6000/predicates.md            | 9 +++++----
 gcc/testsuite/gcc.target/powerpc/pr98092.c | 7 +++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md
index 69f3c709abb..859af75dfbd 100644
--- a/gcc/config/rs6000/predicates.md
+++ b/gcc/config/rs6000/predicates.md
@@ -1208,10 +1208,11 @@
 (define_predicate "branch_comparison_operator"
    (and (match_operand 0 "comparison_operator")
 	(match_test "GET_MODE_CLASS (GET_MODE (XEXP (op, 0))) == MODE_CC")
-	(if_then_else (match_test "GET_MODE (XEXP (op, 0)) == CCFPmode
-				   && !flag_finite_math_only")
-		      (match_code "lt,gt,eq,unordered,unge,unle,ne,ordered")
-		      (match_code "lt,ltu,le,leu,gt,gtu,ge,geu,eq,ne"))
+	(if_then_else (match_test "GET_MODE (XEXP (op, 0)) == CCFPmode")
+	  (if_then_else (match_test "flag_finite_math_only")
+	    (match_code "lt,le,gt,ge,eq,ne,unordered,ordered")
+	    (match_code "lt,gt,eq,unordered,unge,unle,ne,ordered"))
+	  (match_code "lt,ltu,le,leu,gt,gtu,ge,geu,eq,ne"))
 	(match_test "validate_condition_mode (GET_CODE (op),
 					      GET_MODE (XEXP (op, 0))),
 		     1")))
diff --git a/gcc/testsuite/gcc.target/powerpc/pr98092.c b/gcc/testsuite/gcc.target/powerpc/pr98092.c
new file mode 100644
index 00000000000..03eab5a24ef
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr98092.c
@@ -0,0 +1,7 @@
+/* { dg-options "-mdejagnu-cpu=power9 -ffinite-math-only" } */
+
+int
+h9 (__attribute__ ((altivec (vector__))) char un)
+{
+  return (__builtin_vec_bcdinvalid (un));
+}