From 5bcebc253c1637d3a5b957abc7460c49a670c4de Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 27 Aug 2013 10:47:49 -0700 Subject: [PATCH] tcg-i386: Don't perform GETPC adjustment in TCG code Since we now perform it inside the helper, no need to do it here. This also lets us perform a tail-call from the store slow path to the helper. Reviewed-by: Aurelien Jarno Signed-off-by: Richard Henderson --- tcg/i386/tcg-target.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c index cde134f60f..28ed55a096 100644 --- a/tcg/i386/tcg-target.c +++ b/tcg/i386/tcg-target.c @@ -1481,12 +1481,6 @@ static void add_qemu_ldst_label(TCGContext *s, } } -/* See the GETPC definition in include/exec/exec-all.h. */ -static inline uintptr_t do_getpc(uint8_t *raddr) -{ - return (uintptr_t)raddr - 1; -} - /* * Generate code for the slow path for a load at the end of block */ @@ -1520,14 +1514,14 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l) tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index); ofs += 4; - tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, do_getpc(l->raddr)); + tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, (uintptr_t)l->raddr); } else { tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0); /* The second argument is already loaded with addrlo. */ tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[2], l->mem_index); tcg_out_movi(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[3], - do_getpc(l->raddr)); + (uintptr_t)l->raddr); } tcg_out_calli(s, (uintptr_t)qemu_ld_helpers[s_bits]); @@ -1582,6 +1576,7 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l) int opc = l->opc; int s_bits = opc & 3; uint8_t **label_ptr = &l->label_ptr[0]; + TCGReg retaddr; /* resolve label address */ *(uint32_t *)label_ptr[0] = (uint32_t)(s->code_ptr - label_ptr[0] - 4); @@ -1614,10 +1609,10 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l) tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index); ofs += 4; - tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, do_getpc(l->raddr)); + retaddr = TCG_REG_EAX; + tcg_out_movi(s, TCG_TYPE_I32, retaddr, (uintptr_t)l->raddr); + tcg_out_st(s, TCG_TYPE_I32, retaddr, TCG_REG_ESP, ofs); } else { - uintptr_t pc; - tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0); /* The second argument is already loaded with addrlo. */ tcg_out_mov(s, (opc == 3 ? TCG_TYPE_I64 : TCG_TYPE_I32), @@ -1625,19 +1620,19 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l) tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[3], l->mem_index); - pc = do_getpc(l->raddr); if (ARRAY_SIZE(tcg_target_call_iarg_regs) > 4) { - tcg_out_movi(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[4], pc); - } else if (pc == (int32_t)pc) { - tcg_out_sti(s, TCG_TYPE_PTR, TCG_REG_ESP, 0, pc); + retaddr = tcg_target_call_iarg_regs[4]; + tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr); } else { - tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_RAX, pc); - tcg_out_st(s, TCG_TYPE_PTR, TCG_REG_RAX, TCG_REG_ESP, 0); + retaddr = TCG_REG_RAX; + tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr); + tcg_out_st(s, TCG_TYPE_PTR, retaddr, TCG_REG_ESP, 0); } } - tcg_out_calli(s, (uintptr_t)qemu_st_helpers[s_bits]); - tcg_out_jmp(s, (uintptr_t)l->raddr); + /* "Tail call" to the helper, with the return address back inline. */ + tcg_out_push(s, retaddr); + tcg_out_jmp(s, (uintptr_t)qemu_st_helpers[s_bits]); } /*