https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109279
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-03-24
Status|UNCONFIRMED |NEW
Summary|[13 Regression] RISC-V: |RISC-V: complex constants
|complex constants |synthesized should be
|synthesized vs. fetching |improved
|from constant pool |
Ever confirmed|0 |1
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Take:
long long f(void)
{
return 0x0101010101010101ull;
}
---- CUT ----
This should be done as:
li a0,16842752
addi a0,a0,257
slli a1,a0,32
or a0,a0,a1
Which is what this produces:
```
long long f(void)
{
unsigned t = 16843009;
long long t1 = t;
long long t2 = ((unsigned long long )t) << 32;
asm("":"+r"(t1));
return t1 | t2;
}
```
I suspect: 0x0080402010080400ULL should be done as two 32bit with a shift/or
added too. Will definitely improve complex constants forming too.
Right now the backend does (const<<16+const)<<16+const... which is just so bad.
