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authorRichard Henderson <rth@twiddle.net>2013-08-27 10:47:49 -0700
committerRichard Henderson <rth@twiddle.net>2013-09-02 09:08:30 -0700
commit5bcebc253c1637d3a5b957abc7460c49a670c4de (patch)
tree0d23f937045c3507e665b23595760a7e750026a7
parent0f842f8a246f2b5b51a11c13f933bf7a90ae8e96 (diff)
downloadqemu-arm-5bcebc253c1637d3a5b957abc7460c49a670c4de.tar.gz
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 <aurelien@aurel32.net> Signed-off-by: Richard Henderson <rth@twiddle.net>
-rw-r--r--tcg/i386/tcg-target.c33
1 files 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]);
}
/*