tcg/i386: Convert tcg_out_qemu_ld_slow_path

Use tcg_out_ld_helper_args and tcg_out_ld_helper_ret.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/i386/tcg-target.c.inc

@@ -1802,13 +1802,37 @@ static void * const qemu_st_helpers[(MO_SIZE | MO_BSWAP) + 1] = {
     [MO_BEUQ] = helper_be_stq_mmu,
 };
 
+/*
+ * Because i686 has no register parameters and because x86_64 has xchg
+ * to handle addr/data register overlap, we have placed all input arguments
+ * before we need might need a scratch reg.
+ *
+ * Even then, a scratch is only needed for l->raddr.  Rather than expose
+ * a general-purpose scratch when we don't actually know it's available,
+ * use the ra_gen hook to load into RAX if needed.
+ */
+#if TCG_TARGET_REG_BITS == 64
+static TCGReg ldst_ra_gen(TCGContext *s, const TCGLabelQemuLdst *l, int arg)
+{
+    if (arg < 0) {
+        arg = TCG_REG_RAX;
+    }
+    tcg_out_movi(s, TCG_TYPE_PTR, arg, (uintptr_t)l->raddr);
+    return arg;
+}
+static const TCGLdstHelperParam ldst_helper_param = {
+    .ra_gen = ldst_ra_gen
+};
+#else
+static const TCGLdstHelperParam ldst_helper_param = { };
+#endif
+
 /*
  * Generate code for the slow path for a load at the end of block
  */
 static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
 {
-    MemOpIdx oi = l->oi;
-    MemOp opc = get_memop(oi);
+    MemOp opc = get_memop(l->oi);
     tcg_insn_unit **label_ptr = &l->label_ptr[0];
 
     /* resolve label address */
@@ -1817,49 +1841,10 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
         tcg_patch32(label_ptr[1], s->code_ptr - label_ptr[1] - 4);
     }
 
-    if (TCG_TARGET_REG_BITS == 32) {
-        int ofs = 0;
-
-        tcg_out_st(s, TCG_TYPE_PTR, TCG_AREG0, TCG_REG_ESP, ofs);
-        ofs += 4;
-
-        tcg_out_st(s, TCG_TYPE_I32, l->addrlo_reg, TCG_REG_ESP, ofs);
-        ofs += 4;
-
-        if (TARGET_LONG_BITS == 64) {
-            tcg_out_st(s, TCG_TYPE_I32, l->addrhi_reg, TCG_REG_ESP, ofs);
-            ofs += 4;
-        }
-
-        tcg_out_sti(s, TCG_TYPE_I32, oi, TCG_REG_ESP, ofs);
-        ofs += 4;
-
-        tcg_out_sti(s, TCG_TYPE_PTR, (uintptr_t)l->raddr, TCG_REG_ESP, ofs);
-    } else {
-        tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
-        tcg_out_mov(s, TCG_TYPE_TL, tcg_target_call_iarg_regs[1],
-                    l->addrlo_reg);
-        tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[2], oi);
-        tcg_out_movi(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[3],
-                     (uintptr_t)l->raddr);
-    }
-
+    tcg_out_ld_helper_args(s, l, &ldst_helper_param);
     tcg_out_branch(s, 1, qemu_ld_helpers[opc & (MO_BSWAP | MO_SIZE)]);
+    tcg_out_ld_helper_ret(s, l, false, &ldst_helper_param);
 
-    if (TCG_TARGET_REG_BITS == 32 && (opc & MO_SIZE) == MO_64) {
-        TCGMovExtend ext[2] = {
-            { .dst = l->datalo_reg, .dst_type = TCG_TYPE_I32,
-              .src = TCG_REG_EAX, .src_type = TCG_TYPE_I32, .src_ext = MO_UL },
-            { .dst = l->datahi_reg, .dst_type = TCG_TYPE_I32,
-              .src = TCG_REG_EDX, .src_type = TCG_TYPE_I32, .src_ext = MO_UL },
-        };
-        tcg_out_movext2(s, &ext[0], &ext[1], -1);
-    } else {
-        tcg_out_movext(s, l->type, l->datalo_reg,
-                       TCG_TYPE_REG, opc & MO_SSIZE, TCG_REG_EAX);
-    }
-
-    /* Jump to the code corresponding to next IR of qemu_st */
     tcg_out_jmp(s, l->raddr);
     return true;
 }