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 --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md
index 69f3c70..859af75 100644 (file)
--- 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 (file)
index 0000000..03eab5a
--- /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));
+}