From 5767c23140f2c92b899d9caeaa8e08711cb63868 Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Sun, 25 Mar 2012 21:21:46 +0200
Subject: [PATCH] tcg-sparc: Clean up cruft stemming from attempts to use
global registers.
Don't use -ffixed-gN. Don't link statically. Don't save/restore
AREG0 around calls. Don't allocate space on the stack for AREG0 save.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
configure | 12 -----------
tcg/sparc/tcg-target.c | 55 +++++++++++++++++---------------------------------
tcg/sparc/tcg-target.h | 18 +++++++----------
3 files changed, 26 insertions(+), 59 deletions(-)
diff --git a/configure b/configure
index 9139b5c..8ffddf4 100755
--- a/configure
+++ b/configure
@@ -868,19 +868,11 @@ case "$cpu" in
sparc)
LDFLAGS="-m32 $LDFLAGS"
QEMU_CFLAGS="-m32 -mcpu=ultrasparc $QEMU_CFLAGS"
- QEMU_CFLAGS="-ffixed-g2 -ffixed-g3 $QEMU_CFLAGS"
- if test "$solaris" = "no" ; then
- QEMU_CFLAGS="-ffixed-g1 -ffixed-g6 $QEMU_CFLAGS"
- fi
host_guest_base="yes"
;;
sparc64)
LDFLAGS="-m64 $LDFLAGS"
QEMU_CFLAGS="-m64 -mcpu=ultrasparc $QEMU_CFLAGS"
- QEMU_CFLAGS="-ffixed-g5 -ffixed-g6 -ffixed-g7 $QEMU_CFLAGS"
- if test "$solaris" != "no" ; then
- QEMU_CFLAGS="-ffixed-g1 $QEMU_CFLAGS"
- fi
host_guest_base="yes"
;;
s390)
@@ -4055,10 +4047,6 @@ fi
if test "$target_linux_user" = "yes" -o "$target_bsd_user" = "yes" ; then
case "$ARCH" in
- sparc)
- # -static is used to avoid g1/g3 usage by the dynamic linker
- ldflags="$linker_script -static $ldflags"
- ;;
alpha | s390x)
# The default placement of the application is fine.
;;
diff --git a/tcg/sparc/tcg-target.c b/tcg/sparc/tcg-target.c
index 9ab5746..e625aa3 100644
--- a/tcg/sparc/tcg-target.c
+++ b/tcg/sparc/tcg-target.c
@@ -161,7 +161,6 @@ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
tcg_regset_reset_reg(ct->u.regs, TCG_REG_O0);
tcg_regset_reset_reg(ct->u.regs, TCG_REG_O1);
tcg_regset_reset_reg(ct->u.regs, TCG_REG_O2);
- tcg_regset_reset_reg(ct->u.regs, TCG_REG_O3);
break;
case 'I':
ct->ct |= TCG_CT_CONST_S11;
@@ -681,11 +680,22 @@ static void tcg_out_setcond2_i32(TCGContext *s, TCGCond cond, TCGArg ret,
/* Generate global QEMU prologue and epilogue code */
static void tcg_target_qemu_prologue(TCGContext *s)
{
- tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_CALL_STACK_OFFSET,
- CPU_TEMP_BUF_NLONGS * (int)sizeof(long));
+ int tmp_buf_size, frame_size;
+
+ /* The TCG temp buffer is at the top of the frame, immediately
+ below the frame pointer. */
+ tmp_buf_size = CPU_TEMP_BUF_NLONGS * (int)sizeof(long);
+ tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_STACK_BIAS - tmp_buf_size,
+ tmp_buf_size);
+
+ /* TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is
+ otherwise the minimal frame usable by callees. */
+ frame_size = TCG_TARGET_CALL_STACK_OFFSET - TCG_TARGET_STACK_BIAS;
+ frame_size += TCG_STATIC_CALL_ARGS_SIZE + tmp_buf_size;
+ frame_size += TCG_TARGET_STACK_ALIGN - 1;
+ frame_size &= -TCG_TARGET_STACK_ALIGN;
tcg_out32(s, SAVE | INSN_RD(TCG_REG_O6) | INSN_RS1(TCG_REG_O6) |
- INSN_IMM13(-(TCG_TARGET_STACK_MINFRAME +
- CPU_TEMP_BUF_NLONGS * (int)sizeof(long))));
+ INSN_IMM13(-frame_size));
#ifdef CONFIG_USE_GUEST_BASE
if (GUEST_BASE != 0) {
@@ -698,6 +708,8 @@ static void tcg_target_qemu_prologue(TCGContext *s)
INSN_RS2(TCG_REG_G0));
/* delay slot */
tcg_out_nop(s);
+
+ /* No epilogue required. We issue ret + restore directly in the TB. */
}
#if defined(CONFIG_SOFTMMU)
@@ -880,12 +892,6 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int sizeop)
tcg_out_mov(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n++],
args[addrlo_idx]);
- /* Store AREG0 in stack to avoid ugly glibc bugs that mangle
- global registers */
- tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
-
/* qemu_ld_helper[s_bits](arg0, arg1) */
tcg_out32(s, CALL | ((((tcg_target_ulong)qemu_ld_helpers[s_bits]
- (tcg_target_ulong)s->code_ptr) >> 2)
@@ -893,11 +899,6 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int sizeop)
/* delay slot */
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[n], memi);
- /* Reload AREG0. */
- tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
-
n = tcg_target_call_oarg_regs[0];
/* datalo = sign_extend(arg0) */
switch (sizeop) {
@@ -1011,12 +1012,6 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int sizeop)
}
tcg_out_mov(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n++], datalo);
- /* Store AREG0 in stack to avoid ugly glibc bugs that mangle
- global registers */
- tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
-
/* qemu_st_helper[s_bits](arg0, arg1, arg2) */
tcg_out32(s, CALL | ((((tcg_target_ulong)qemu_st_helpers[sizeop]
- (tcg_target_ulong)s->code_ptr) >> 2)
@@ -1024,11 +1019,6 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int sizeop)
/* delay slot */
tcg_out_movi(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n], memi);
- /* Reload AREG0. */
- tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
-
*label_ptr |= INSN_OFF19((unsigned long)s->code_ptr -
(unsigned long)label_ptr);
#else
@@ -1091,15 +1081,8 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args,
tcg_out32(s, JMPL | INSN_RD(TCG_REG_O7) | INSN_RS1(TCG_REG_I5) |
INSN_RS2(TCG_REG_G0));
}
- /* Store AREG0 in stack to avoid ugly glibc bugs that mangle
- global registers */
- // delay slot
- tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
- tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK,
- TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE -
- sizeof(long));
+ /* delay slot */
+ tcg_out_nop(s);
break;
case INDEX_op_jmp:
case INDEX_op_br:
diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h
index ee154d0..6314ffb 100644
--- a/tcg/sparc/tcg-target.h
+++ b/tcg/sparc/tcg-target.h
@@ -66,20 +66,16 @@ typedef enum {
#define TCG_CT_CONST_S13 0x200
/* used for function call generation */
-#define TCG_REG_CALL_STACK TCG_REG_I6
+#define TCG_REG_CALL_STACK TCG_REG_O6
#if TCG_TARGET_REG_BITS == 64
-// Reserve space for AREG0
-#define TCG_TARGET_STACK_MINFRAME (176 + 4 * (int)sizeof(long) + \
- TCG_STATIC_CALL_ARGS_SIZE)
-#define TCG_TARGET_CALL_STACK_OFFSET (2047 - 16)
-#define TCG_TARGET_STACK_ALIGN 16
+#define TCG_TARGET_STACK_BIAS 2047
+#define TCG_TARGET_STACK_ALIGN 16
+#define TCG_TARGET_CALL_STACK_OFFSET (128 + 6*8 + TCG_TARGET_STACK_BIAS)
#else
-// AREG0 + one word for alignment
-#define TCG_TARGET_STACK_MINFRAME (92 + (2 + 1) * (int)sizeof(long) + \
- TCG_STATIC_CALL_ARGS_SIZE)
-#define TCG_TARGET_CALL_STACK_OFFSET TCG_TARGET_STACK_MINFRAME
-#define TCG_TARGET_STACK_ALIGN 8
+#define TCG_TARGET_STACK_BIAS 0
+#define TCG_TARGET_STACK_ALIGN 8
+#define TCG_TARGET_CALL_STACK_OFFSET (64 + 4 + 6*4)
#endif
#if TCG_TARGET_REG_BITS == 64
--
1.7.12.1