On Tue, 2024-09-10 at 16:50 +0800, 梅杰 wrote:
> As for the function `__builtin_rint`, although it exists, however, after
> defining the instruction in `mips.md`, GCC still won't generate `RINT.fmt`
> instruction for MIPS, it generates following code instead:
>
> > lui $28,%hi(__gnu_local_gp)
> > addiu $28,$28,%lo(__gnu_local_gp)
> > lw $25,%call16(rint)($28)
> > .reloc 1f,R_MIPS_JALR,rint
Why?
Whis this:
diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index f147667d63a..0c1ef77a816 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -100,6 +100,7 @@ (define_c_enum "unspec" [
;; Floating-point unspecs.
UNSPEC_FMIN
UNSPEC_FMAX
+ UNSPEC_RINT
;; HI/LO moves.
UNSPEC_MFHI
@@ -8025,6 +8026,14 @@ (define_peephole2
(any_extend:SI (match_dup 3)))])]
"")
+(define_insn "rint<mode>2"
+ [(set (match_operand:SCALARF 0 "register_operand" "=f")
+ (unspec:SCALARF [(match_operand:SCALARF 1 "register_operand" " f")]
+ UNSPEC_RINT))]
+ "mips_isa_rev >= 6"
+ "rint.<fmt>\t%0,%1")
+
+
;; Synchronization instructions.
it works for me:
$ cat t.c
double test(double x)
{
return __builtin_rint(x);
}
$ ./gcc/cc1 t.c -nostdinc -O2 -mips64r6 -mexplicit-relocs -mabi=64
$ grep rint t.s
rint.d $f0,$f12
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
