tcg-ppc64: Fold constant call address into descriptor load

Eliminates one insn per call:

 :  lis     r2,4165
-:  ori     r2,r2,59616
-:  ld      r0,0(r2)
+:  ld      r0,-5920(r2)
 :  mtctr   r0
-:  ld      r2,8(r2)
+:  ld      r2,-5912(r2)
 :  bctrl

Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2013-08-31 06:13:49 -07:00
parent ad94e1a9db
commit d40f3cb112

View file

@ -713,16 +713,24 @@ static void tcg_out_call(TCGContext *s, tcg_target_long arg, int const_arg)
tcg_out32(s, BCLR | BO_ALWAYS | LK);
}
#else
int reg = arg;
TCGReg reg = arg;
int ofs = 0;
if (const_arg) {
/* Fold the low bits of the constant into the addresses below. */
ofs = (int16_t)arg;
if (ofs + 8 < 0x8000) {
arg -= ofs;
} else {
ofs = 0;
}
reg = TCG_REG_R2;
tcg_out_movi(s, TCG_TYPE_I64, reg, arg);
}
tcg_out32(s, LD | TAI(TCG_REG_R0, reg, 0));
tcg_out32(s, LD | TAI(TCG_REG_R0, reg, ofs));
tcg_out32(s, MTSPR | RA(TCG_REG_R0) | CTR);
tcg_out32(s, LD | TAI(TCG_REG_R2, reg, 8));
tcg_out32(s, LD | TAI(TCG_REG_R2, reg, ofs + 8));
tcg_out32(s, BCCTR | BO_ALWAYS | LK);
#endif
}