From d40f3cb1128208d901b6224b52ff36ff05680d28 Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Sat, 31 Aug 2013 06:13:49 -0700
Subject: [PATCH] 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>
---
tcg/ppc64/tcg-target.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
index 5ac62bf40d..8eb04060e6 100644
--- a/tcg/ppc64/tcg-target.c
+++ b/tcg/ppc64/tcg-target.c
@@ -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
}
--
2.30.2