[PATCH v2 53/54] tcg/s390x: Use ALGFR in constructing host address for qemu_ld/st

[Richard Henderson]

Rather than zero-extend the guest address into a register,
use an add instruction which zero-extends the second input.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/s390x/tcg-target.c.inc | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/tcg/s390x/tcg-target.c.inc b/tcg/s390x/tcg-target.c.inc
index 6d7b056931..42d3e13e08 100644
--- a/tcg/s390x/tcg-target.c.inc
+++ b/tcg/s390x/tcg-target.c.inc
@@ -149,6 +149,7 @@ typedef enum S390Opcode {
     RRE_ALGR    = 0xb90a,
     RRE_ALCR    = 0xb998,
     RRE_ALCGR   = 0xb988,
+    RRE_ALGFR   = 0xb91a,
     RRE_CGR     = 0xb920,
     RRE_CLGR    = 0xb921,
     RRE_DLGR    = 0xb987,
@@ -1716,8 +1717,10 @@ static void tcg_out_qemu_st_direct(TCGContext *s, MemOp 
opc, TCGReg data,
 QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) > 0);
 QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) < -(1 << 19));
 
-/* Load and compare a TLB entry, leaving the flags set.  Loads the TLB
-   addend into R2.  Returns a register with the santitized guest address.  */
+/*
+ * Load and compare a TLB entry, leaving the flags set.
+ * Loads the TLB addend and returns the register.
+ */
 static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addr_reg, MemOp opc,
                                int mem_index, bool is_ld)
 {
@@ -1761,12 +1764,7 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg 
addr_reg, MemOp opc,
 
     tcg_out_insn(s, RXY, LG, TCG_REG_R2, TCG_REG_R2, TCG_REG_NONE,
                  offsetof(CPUTLBEntry, addend));
-
-    if (TARGET_LONG_BITS == 32) {
-        tcg_out_ext32u(s, TCG_REG_R3, addr_reg);
-        return TCG_REG_R3;
-    }
-    return addr_reg;
+    return TCG_REG_R2;
 }
 
 static void add_qemu_ldst_label(TCGContext *s, bool is_ld, MemOpIdx oi,
@@ -1892,16 +1890,20 @@ static void tcg_out_qemu_ld(TCGContext* s, TCGReg 
data_reg, TCGReg addr_reg,
 #ifdef CONFIG_SOFTMMU
     unsigned mem_index = get_mmuidx(oi);
     tcg_insn_unit *label_ptr;
-    TCGReg base_reg;
+    TCGReg addend;
 
-    base_reg = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 1);
+    addend = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 1);
 
     tcg_out16(s, RI_BRC | (S390_CC_NE << 4));
     label_ptr = s->code_ptr;
     s->code_ptr += 1;
 
-    tcg_out_qemu_ld_direct(s, opc, data_reg, base_reg, TCG_REG_R2, 0);
-
+    if (TARGET_LONG_BITS == 32) {
+        tcg_out_insn(s, RRE, ALGFR, addend, addr_reg);
+        tcg_out_qemu_ld_direct(s, opc, data_reg, addend, TCG_REG_NONE, 0);
+    } else {
+        tcg_out_qemu_ld_direct(s, opc, data_reg, addend, addr_reg, 0);
+    }
     add_qemu_ldst_label(s, 1, oi, data_type, data_reg, addr_reg,
                         s->code_ptr, label_ptr);
 #else
@@ -1924,16 +1926,20 @@ static void tcg_out_qemu_st(TCGContext* s, TCGReg 
data_reg, TCGReg addr_reg,
 #ifdef CONFIG_SOFTMMU
     unsigned mem_index = get_mmuidx(oi);
     tcg_insn_unit *label_ptr;
-    TCGReg base_reg;
+    TCGReg addend;
 
-    base_reg = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 0);
+    addend = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 0);
 
     tcg_out16(s, RI_BRC | (S390_CC_NE << 4));
     label_ptr = s->code_ptr;
     s->code_ptr += 1;
 
-    tcg_out_qemu_st_direct(s, opc, data_reg, base_reg, TCG_REG_R2, 0);
-
+    if (TARGET_LONG_BITS == 32) {
+        tcg_out_insn(s, RRE, ALGFR, addend, addr_reg);
+        tcg_out_qemu_st_direct(s, opc, data_reg, addend, TCG_REG_NONE, 0);
+    } else {
+        tcg_out_qemu_st_direct(s, opc, data_reg, addend, addr_reg, 0);
+    }
     add_qemu_ldst_label(s, 0, oi, data_type, data_reg, addr_reg,
                         s->code_ptr, label_ptr);
 #else
-- 
2.34.1