This makes -fsignaling-nans work correctly, fixing 20 glibc testsuite failures.
The FP quiet compare pattern is ignoring all exceptions, including for SNaNs.
To make this work right when -fsignaling-nan, we need an extra eq compare to
raise an exception, but only when HONOR_SNANS is true. So we get the more
efficient code in the default case, and code that works for the glibc
testsuite when -fsignaling-nans is used.
This was tested with cross riscv32-elf and riscv64-linux builds and checks.
It was also tested with a riscv64-linux glibc build and check
gcc/
* config/riscv/riscv.md (f<quiet_pattern>_quiet<ANYF:mode><X:mode>4):
Add define_expand. Add ! HONOR_SNANS check to current pattern. Add
new pattern using HONOR_SNANS that emits one extra instruction.
---
gcc/config/riscv/riscv.md | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 4162dc578e8..b6c20230ffd 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -1957,19 +1957,41 @@
[(set_attr "type" "fcmp")
(set_attr "mode" "<UNITMODE>")])
-(define_insn "f<quiet_pattern>_quiet<ANYF:mode><X:mode>4"
- [(set (match_operand:X 0 "register_operand" "=r")
+(define_expand "f<quiet_pattern>_quiet<ANYF:mode><X:mode>4"
+ [(parallel [(set (match_operand:X 0 "register_operand")
+ (unspec:X
+ [(match_operand:ANYF 1 "register_operand")
+ (match_operand:ANYF 2 "register_operand")]
+ QUIET_COMPARISON))
+ (clobber (match_scratch:X 3))])]
+ "TARGET_HARD_FLOAT")
+
+(define_insn "*f<quiet_pattern>_quiet<ANYF:mode><X:mode>4_default"
+ [(set (match_operand:X 0 "register_operand" "=r")
(unspec:X
- [(match_operand:ANYF 1 "register_operand" " f")
- (match_operand:ANYF 2 "register_operand" " f")]
- QUIET_COMPARISON))
+ [(match_operand:ANYF 1 "register_operand" " f")
+ (match_operand:ANYF 2 "register_operand" " f")]
+ QUIET_COMPARISON))
(clobber (match_scratch:X 3 "=&r"))]
- "TARGET_HARD_FLOAT"
+ "TARGET_HARD_FLOAT && ! HONOR_SNANS (<ANYF:MODE>mode)"
"frflags\t%3\n\tf<quiet_pattern>.<fmt>\t%0,%1,%2\n\tfsflags %3"
[(set_attr "type" "fcmp")
(set_attr "mode" "<UNITMODE>")
(set (attr "length") (const_int 12))])
+(define_insn "*f<quiet_pattern>_quiet<ANYF:mode><X:mode>4_snan"
+ [(set (match_operand:X 0 "register_operand" "=r")
+ (unspec:X
+ [(match_operand:ANYF 1 "register_operand" " f")
+ (match_operand:ANYF 2 "register_operand" " f")]
+ QUIET_COMPARISON))
+ (clobber (match_scratch:X 3 "=&r"))]
+ "TARGET_HARD_FLOAT && HONOR_SNANS (<ANYF:MODE>mode)"
+ "frflags\t%3\n\tf<quiet_pattern>.<fmt>\t%0,%1,%2\n\tfsflags
%3\n\tfeq.<fmt>\tzero,%1,%2"
+ [(set_attr "type" "fcmp")
+ (set_attr "mode" "<UNITMODE>")
+ (set (attr "length") (const_int 16))])
+
(define_insn "*seq_zero_<X:mode><GPR:mode>"
[(set (match_operand:GPR 0 "register_operand" "=r")
(eq:GPR (match_operand:X 1 "register_operand" " r")
--
2.17.1
