[PULL 62/63] tcg/aarch64: Unset TCG_TARGET_HAS_MEMORY_BSWAP

[Richard Henderson <richard.henderson@linaro.org>]

The memory bswap support in the aarch64 backend merely dates from
a time when it was required.  There is nothing special about the
backend support that could not have been provided by the middle-end
even prior to the introduction of the bswap flags.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/aarch64/tcg-target.h     |  2 +-
 tcg/aarch64/tcg-target.c.inc | 87 +++++++++++++-----------------------
 2 files changed, 32 insertions(+), 57 deletions(-)

diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index ef55f7c185..551baf8da3 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -148,7 +148,7 @@ typedef enum {
 #define TCG_TARGET_HAS_cmpsel_vec       0
 
 #define TCG_TARGET_DEFAULT_MO (0)
-#define TCG_TARGET_HAS_MEMORY_BSWAP     1
+#define TCG_TARGET_HAS_MEMORY_BSWAP     0
 
 void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 
diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
index 72aa7e0e74..5924977b42 100644
--- a/tcg/aarch64/tcg-target.c.inc
+++ b/tcg/aarch64/tcg-target.c.inc
@@ -1547,28 +1547,34 @@ static void tcg_out_cltz(TCGContext *s, TCGType ext, TCGReg d,
 /* helper signature: helper_ret_ld_mmu(CPUState *env, target_ulong addr,
  *                                     TCGMemOpIdx oi, uintptr_t ra)
  */
-static void * const qemu_ld_helpers[16] = {
-    [MO_UB]   = helper_ret_ldub_mmu,
-    [MO_LEUW] = helper_le_lduw_mmu,
-    [MO_LEUL] = helper_le_ldul_mmu,
-    [MO_LEQ]  = helper_le_ldq_mmu,
-    [MO_BEUW] = helper_be_lduw_mmu,
-    [MO_BEUL] = helper_be_ldul_mmu,
-    [MO_BEQ]  = helper_be_ldq_mmu,
+static void * const qemu_ld_helpers[4] = {
+    [MO_8]  = helper_ret_ldub_mmu,
+#ifdef HOST_WORDS_BIGENDIAN
+    [MO_16] = helper_be_lduw_mmu,
+    [MO_32] = helper_be_ldul_mmu,
+    [MO_64] = helper_be_ldq_mmu,
+#else
+    [MO_16] = helper_le_lduw_mmu,
+    [MO_32] = helper_le_ldul_mmu,
+    [MO_64] = helper_le_ldq_mmu,
+#endif
 };
 
 /* helper signature: helper_ret_st_mmu(CPUState *env, target_ulong addr,
  *                                     uintxx_t val, TCGMemOpIdx oi,
  *                                     uintptr_t ra)
  */
-static void * const qemu_st_helpers[16] = {
-    [MO_UB]   = helper_ret_stb_mmu,
-    [MO_LEUW] = helper_le_stw_mmu,
-    [MO_LEUL] = helper_le_stl_mmu,
-    [MO_LEQ]  = helper_le_stq_mmu,
-    [MO_BEUW] = helper_be_stw_mmu,
-    [MO_BEUL] = helper_be_stl_mmu,
-    [MO_BEQ]  = helper_be_stq_mmu,
+static void * const qemu_st_helpers[4] = {
+    [MO_8]  = helper_ret_stb_mmu,
+#ifdef HOST_WORDS_BIGENDIAN
+    [MO_16] = helper_be_stw_mmu,
+    [MO_32] = helper_be_stl_mmu,
+    [MO_64] = helper_be_stq_mmu,
+#else
+    [MO_16] = helper_le_stw_mmu,
+    [MO_32] = helper_le_stl_mmu,
+    [MO_64] = helper_le_stq_mmu,
+#endif
 };
 
 static inline void tcg_out_adr(TCGContext *s, TCGReg rd, const void *target)
@@ -1592,7 +1598,7 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     tcg_out_mov(s, TARGET_LONG_BITS == 64, TCG_REG_X1, lb->addrlo_reg);
     tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_X2, oi);
     tcg_out_adr(s, TCG_REG_X3, lb->raddr);
-    tcg_out_call(s, qemu_ld_helpers[opc & (MO_BSWAP | MO_SIZE)]);
+    tcg_out_call(s, qemu_ld_helpers[opc & MO_SIZE]);
     if (opc & MO_SIGN) {
         tcg_out_sxt(s, lb->type, size, lb->datalo_reg, TCG_REG_X0);
     } else {
@@ -1618,7 +1624,7 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     tcg_out_mov(s, size == MO_64, TCG_REG_X2, lb->datalo_reg);
     tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_X3, oi);
     tcg_out_adr(s, TCG_REG_X4, lb->raddr);
-    tcg_out_call(s, qemu_st_helpers[opc & (MO_BSWAP | MO_SIZE)]);
+    tcg_out_call(s, qemu_st_helpers[opc & MO_SIZE]);
     tcg_out_goto(s, lb->raddr);
     return true;
 }
@@ -1714,7 +1720,8 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, MemOp memop, TCGType ext,
                                    TCGReg data_r, TCGReg addr_r,
                                    TCGType otype, TCGReg off_r)
 {
-    const MemOp bswap = memop & MO_BSWAP;
+    /* Byte swapping is left to middle-end expansion. */
+    tcg_debug_assert((memop & MO_BSWAP) == 0);
 
     switch (memop & MO_SSIZE) {
     case MO_UB:
@@ -1726,40 +1733,19 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, MemOp memop, TCGType ext,
         break;
     case MO_UW:
         tcg_out_ldst_r(s, I3312_LDRH, data_r, addr_r, otype, off_r);
-        if (bswap) {
-            tcg_out_rev(s, TCG_TYPE_I32, MO_16, data_r, data_r);
-        }
         break;
     case MO_SW:
-        if (bswap) {
-            tcg_out_ldst_r(s, I3312_LDRH, data_r, addr_r, otype, off_r);
-            tcg_out_rev(s, TCG_TYPE_I32, MO_16, data_r, data_r);
-            tcg_out_sxt(s, ext, MO_16, data_r, data_r);
-        } else {
-            tcg_out_ldst_r(s, (ext ? I3312_LDRSHX : I3312_LDRSHW),
-                           data_r, addr_r, otype, off_r);
-        }
+        tcg_out_ldst_r(s, (ext ? I3312_LDRSHX : I3312_LDRSHW),
+                       data_r, addr_r, otype, off_r);
         break;
     case MO_UL:
         tcg_out_ldst_r(s, I3312_LDRW, data_r, addr_r, otype, off_r);
-        if (bswap) {
-            tcg_out_rev(s, TCG_TYPE_I32, MO_32, data_r, data_r);
-        }
         break;
     case MO_SL:
-        if (bswap) {
-            tcg_out_ldst_r(s, I3312_LDRW, data_r, addr_r, otype, off_r);
-            tcg_out_rev(s, TCG_TYPE_I32, MO_32, data_r, data_r);
-            tcg_out_sxt(s, TCG_TYPE_I64, MO_32, data_r, data_r);
-        } else {
-            tcg_out_ldst_r(s, I3312_LDRSWX, data_r, addr_r, otype, off_r);
-        }
+        tcg_out_ldst_r(s, I3312_LDRSWX, data_r, addr_r, otype, off_r);
         break;
     case MO_Q:
         tcg_out_ldst_r(s, I3312_LDRX, data_r, addr_r, otype, off_r);
-        if (bswap) {
-            tcg_out_rev(s, TCG_TYPE_I64, MO_64, data_r, data_r);
-        }
         break;
     default:
         tcg_abort();
@@ -1770,31 +1756,20 @@ static void tcg_out_qemu_st_direct(TCGContext *s, MemOp memop,
                                    TCGReg data_r, TCGReg addr_r,
                                    TCGType otype, TCGReg off_r)
 {
-    const MemOp bswap = memop & MO_BSWAP;
+    /* Byte swapping is left to middle-end expansion. */
+    tcg_debug_assert((memop & MO_BSWAP) == 0);
 
     switch (memop & MO_SIZE) {
     case MO_8:
         tcg_out_ldst_r(s, I3312_STRB, data_r, addr_r, otype, off_r);
         break;
     case MO_16:
-        if (bswap && data_r != TCG_REG_XZR) {
-            tcg_out_rev(s, TCG_TYPE_I32, MO_16, TCG_REG_TMP, data_r);
-            data_r = TCG_REG_TMP;
-        }
         tcg_out_ldst_r(s, I3312_STRH, data_r, addr_r, otype, off_r);
         break;
     case MO_32:
-        if (bswap && data_r != TCG_REG_XZR) {
-            tcg_out_rev(s, TCG_TYPE_I32, MO_32, TCG_REG_TMP, data_r);
-            data_r = TCG_REG_TMP;
-        }
         tcg_out_ldst_r(s, I3312_STRW, data_r, addr_r, otype, off_r);
         break;
     case MO_64:
-        if (bswap && data_r != TCG_REG_XZR) {
-            tcg_out_rev(s, TCG_TYPE_I64, MO_64, TCG_REG_TMP, data_r);
-            data_r = TCG_REG_TMP;
-        }
         tcg_out_ldst_r(s, I3312_STRX, data_r, addr_r, otype, off_r);
         break;
     default:
-- 
2.25.1