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authorRichard Henderson <rth@twiddle.net>2014-03-25 17:11:37 -0400
committerRichard Henderson <rth@twiddle.net>2014-03-27 16:33:01 -0400
commit1a8e80d7e82aa385ad887dba5d039e399a18264b (patch)
treea908a6638484be7de25484dc08ab135d9fb677f1 /tcg/arm
parent9c5793c5036c7608ff2c87846c6d11f904c08b58 (diff)
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tcg-arm: Avoid ldrd/strd for user-only emulation
The arm ldrd/strd insns must cause alignment traps, whereas at least for armv7 ldr/str must handle unaligned operations. While this is hardly the only problem facing user-only emu, this solves one problem for i386 on armv7 emulation. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reported-by: Huw Davies <huw@codeweavers.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/arm')
-rw-r--r--tcg/arm/tcg-target.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index c8884b3..a65fc65 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -60,6 +60,13 @@ static int arm_arch = __ARM_ARCH;
bool use_idiv_instructions;
#endif
+/* ??? Ought to think about changing CONFIG_SOFTMMU to always defined. */
+#ifdef CONFIG_SOFTMMU
+# define USING_SOFTMMU 1
+#else
+# define USING_SOFTMMU 0
+#endif
+
#ifndef NDEBUG
static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {
"%r0",
@@ -1404,7 +1411,9 @@ static inline void tcg_out_qemu_ld_index(TCGContext *s, TCGMemOp opc,
TCGReg dl = (bswap ? datahi : datalo);
TCGReg dh = (bswap ? datalo : datahi);
- if (use_armv6_instructions && (dl & 1) == 0 && dh == dl + 1) {
+ /* Avoid ldrd for user-only emulation, to handle unaligned. */
+ if (USING_SOFTMMU && use_armv6_instructions
+ && (dl & 1) == 0 && dh == dl + 1) {
tcg_out_ldrd_r(s, COND_AL, dl, addrlo, addend);
} else if (dl != addend) {
tcg_out_ld32_rwb(s, COND_AL, dl, addend, addrlo);
@@ -1463,7 +1472,9 @@ static inline void tcg_out_qemu_ld_direct(TCGContext *s, TCGMemOp opc,
TCGReg dl = (bswap ? datahi : datalo);
TCGReg dh = (bswap ? datalo : datahi);
- if (use_armv6_instructions && (dl & 1) == 0 && dh == dl + 1) {
+ /* Avoid ldrd for user-only emulation, to handle unaligned. */
+ if (USING_SOFTMMU && use_armv6_instructions
+ && (dl & 1) == 0 && dh == dl + 1) {
tcg_out_ldrd_8(s, COND_AL, dl, addrlo, 0);
} else if (dl == addrlo) {
tcg_out_ld32_12(s, COND_AL, dh, addrlo, bswap ? 0 : 4);
@@ -1548,12 +1559,13 @@ static inline void tcg_out_qemu_st_index(TCGContext *s, int cond, TCGMemOp opc,
}
break;
case MO_64:
+ /* Avoid strd for user-only emulation, to handle unaligned. */
if (bswap) {
tcg_out_bswap32(s, cond, TCG_REG_R0, datahi);
tcg_out_st32_rwb(s, cond, TCG_REG_R0, addend, addrlo);
tcg_out_bswap32(s, cond, TCG_REG_R0, datalo);
tcg_out_st32_12(s, cond, TCG_REG_R0, addend, 4);
- } else if (use_armv6_instructions
+ } else if (USING_SOFTMMU && use_armv6_instructions
&& (datalo & 1) == 0 && datahi == datalo + 1) {
tcg_out_strd_r(s, cond, datalo, addrlo, addend);
} else {
@@ -1592,12 +1604,13 @@ static inline void tcg_out_qemu_st_direct(TCGContext *s, TCGMemOp opc,
}
break;
case MO_64:
+ /* Avoid strd for user-only emulation, to handle unaligned. */
if (bswap) {
tcg_out_bswap32(s, COND_AL, TCG_REG_R0, datahi);
tcg_out_st32_12(s, COND_AL, TCG_REG_R0, addrlo, 0);
tcg_out_bswap32(s, COND_AL, TCG_REG_R0, datalo);
tcg_out_st32_12(s, COND_AL, TCG_REG_R0, addrlo, 4);
- } else if (use_armv6_instructions
+ } else if (USING_SOFTMMU && use_armv6_instructions
&& (datalo & 1) == 0 && datahi == datalo + 1) {
tcg_out_strd_8(s, COND_AL, datalo, addrlo, 0);
} else {