[Qemu-devel] [PATCH 43/62] tcg-s390: Tidy tcg_prepare_qemu_ldst.

[Richard Henderson]

Make use of the reg+reg+disp addressing mode to eliminate
redundant additions.  Make use of the load-and-operate insns.
Avoid an extra register copy when using the 64-bit shift insns.

Signed-off-by: Richard Henderson <r...@twiddle.net>
---
 tcg/s390/tcg-target.c |   56 ++++++++++++++++--------------------------------
 1 files changed, 19 insertions(+), 37 deletions(-)

diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 5d2efaa..000a646 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -135,6 +135,7 @@ typedef enum S390Opcode {
     RS_SRA      = 0x8a,
     RS_SRL      = 0x88,
 
+    RXY_AG      = 0xe308,
     RXY_CG      = 0xe320,
     RXY_LB      = 0xe376,
     RXY_LG      = 0xe304,
@@ -962,24 +963,16 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, TCGReg 
data_reg,
 {
     const TCGReg arg0 = TCG_REG_R2;
     const TCGReg arg1 = TCG_REG_R3;
-    const TCGReg arg2 = TCG_REG_R4;
-    int s_bits;
+    int s_bits = opc & 3;
     uint16_t *label1_ptr;
+    tcg_target_long ofs;
 
-    if (is_store) {
-        s_bits = opc;
+    if (TARGET_LONG_BITS == 32) {
+        tgen_ext32u(s, arg0, addr_reg);
     } else {
-        s_bits = opc & 3;
+        tcg_out_mov(s, arg0, addr_reg);
     }
 
-#if TARGET_LONG_BITS == 32
-    tgen_ext32u(s, arg1, addr_reg);
-    tgen_ext32u(s, arg0, addr_reg);
-#else
-    tcg_out_mov(s, arg1, addr_reg);
-    tcg_out_mov(s, arg0, addr_reg);
-#endif
-
     tcg_out_sh64(s, RSY_SRLG, arg1, addr_reg, SH64_REG_NONE,
                  TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS);
 
@@ -987,17 +980,19 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, TCGReg 
data_reg,
     tgen64_andi(s, arg1, (CPU_TLB_SIZE - 1) << CPU_TLB_ENTRY_BITS);
 
     if (is_store) {
-        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
-                     offsetof(CPUState, tlb_table[mem_index][0].addr_write));
+        ofs = offsetof(CPUState, tlb_table[mem_index][0].addr_write);
     } else {
-        tcg_out_movi(s, TCG_TYPE_PTR, TCG_TMP0,
-                     offsetof(CPUState, tlb_table[mem_index][0].addr_read));
+        ofs = offsetof(CPUState, tlb_table[mem_index][0].addr_read);
     }
-    tcg_out_insn(s, RRE, AGR, arg1, TCG_TMP0);
+    assert(ofs < 0x80000);
 
-    tcg_out_insn(s, RRE, AGR, arg1, TCG_AREG0);
+    tcg_out_insn(s, RXY, CG, arg0, arg1, TCG_AREG0, ofs);
 
-    tcg_out_insn(s, RXY, CG, arg0, arg1, 0, 0);
+    if (TARGET_LONG_BITS == 32) {
+        tgen_ext32u(s, arg0, addr_reg);
+    } else {
+        tcg_out_mov(s, arg0, addr_reg);
+    }
 
     label1_ptr = (uint16_t*)s->code_ptr;
 
@@ -1005,15 +1000,9 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, TCGReg 
data_reg,
     tcg_out_insn(s, RI, BRC, S390_CC_EQ, 0);
 
     /* call load/store helper */
-#if TARGET_LONG_BITS == 32
-    tgen_ext32u(s, arg0, addr_reg);
-#else
-    tcg_out_mov(s, arg0, addr_reg);
-#endif
-
     if (is_store) {
         tcg_out_mov(s, arg1, data_reg);
-        tcg_out_movi(s, TCG_TYPE_I32, arg2, mem_index);
+        tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_R4, mem_index);
         tgen_calli(s, (tcg_target_ulong)qemu_st_helpers[s_bits]);
     } else {
         tcg_out_movi(s, TCG_TYPE_I32, arg1, mem_index);
@@ -1046,17 +1035,10 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, TCGReg 
data_reg,
     *(label1_ptr + 1) = ((unsigned long)s->code_ptr -
                          (unsigned long)label1_ptr) >> 1;
 
-    if (is_store) {
-        tcg_out_insn(s, RXY, LG, arg1, arg1, 0,
-                     offsetof(CPUTLBEntry, addend)
-                     - offsetof(CPUTLBEntry, addr_write));
-    } else {
-        tcg_out_insn(s, RXY, LG, arg1, arg1, 0,
-                     offsetof(CPUTLBEntry, addend)
-                     - offsetof(CPUTLBEntry, addr_read));
-    }
+    ofs = offsetof(CPUState, tlb_table[mem_index][0].addend);
+    assert(ofs < 0x80000);
 
-    tcg_out_insn(s, RRE, AGR, arg0, arg1);
+    tcg_out_insn(s, RXY, AG, arg0, arg1, TCG_AREG0, ofs);
 }
 
 static void tcg_finish_qemu_ldst(TCGContext* s, uint16_t *label2_ptr)
-- 
1.7.0.1