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tcg: Optimize spills of constants

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While we can store constants via constrants on INDEX_op_st_i32 et al,
we weren't able to spill constants to backing store.

Add a new backend interface, tcg_out_sti, which may store the constant
(and is allowed to fail).  Rearrange the temp_* helpers so that we only
attempt to directly store a constant when the temp is becoming dead/free.

Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2016-06-19 22:59:13 -07:00
parent 120c1084ed
commit 59d7c14eef
10 changed files with 169 additions and 81 deletions
Download patch file Download diff file Expand all files Collapse all files

21
tcg/i386/tcg-target.inc.c
View file

@ -710,12 +710,19 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, TCGReg arg,
tcg_out_modrm_offset(s, opc, arg, arg1, arg2);
}
static inline void tcg_out_sti(TCGContext *s, TCGType type, TCGReg base,
tcg_target_long ofs, tcg_target_long val)
static bool tcg_out_sti(TCGContext *s, TCGType type, TCGArg val,
TCGReg base, intptr_t ofs)
{
int opc = OPC_MOVL_EvIz + (type == TCG_TYPE_I64 ? P_REXW : 0);
tcg_out_modrm_offset(s, opc, 0, base, ofs);
int rexw = 0;
if (TCG_TARGET_REG_BITS == 64 && type == TCG_TYPE_I64) {
if (val != (int32_t)val) {
return false;
}
rexw = P_REXW;
}
tcg_out_modrm_offset(s, OPC_MOVL_EvIz | rexw, 0, base, ofs);
tcg_out32(s, val);
return true;
}
static void tcg_out_shifti(TCGContext *s, int subopc, int reg, int count)
@ -1321,10 +1328,10 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
ofs += 4;
}
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, oi);
tcg_out_sti(s, TCG_TYPE_I32, oi, TCG_REG_ESP, ofs);
ofs += 4;
tcg_out_sti(s, TCG_TYPE_PTR, TCG_REG_ESP, ofs, (uintptr_t)l->raddr);
tcg_out_sti(s, TCG_TYPE_PTR, (uintptr_t)l->raddr, TCG_REG_ESP, ofs);
} else {
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
/* The second argument is already loaded with addrlo. */
@ -1413,7 +1420,7 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
ofs += 4;
}
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, oi);
tcg_out_sti(s, TCG_TYPE_I32, oi, TCG_REG_ESP, ofs);
ofs += 4;
retaddr = TCG_REG_EAX;