[Qemu-devel] [PATCH 22/62] tcg-s390: Tidy branches.

[Richard Henderson]

Add tgen_gotoi to implement conditional and unconditional direct
branches.  Add tgen_branch to implement branches to labels.

Signed-off-by: Richard Henderson <address@hidden>
---
 tcg/s390/tcg-target.c |   96 ++++++++++++++++++++++++++++---------------------
 1 files changed, 55 insertions(+), 41 deletions(-)

diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 21ad1a3..f4dab1a 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -41,8 +41,9 @@
    halves of the 16-bit quantity may appear 32 bits apart in the insn.
    This makes it easy to copy the values from the tables in Appendix B.  */
 typedef enum S390Opcode {
-    RIL_LARL    = 0xc000,
     RIL_BRASL   = 0xc005,
+    RIL_BRCL    = 0xc004,
+    RIL_LARL    = 0xc000,
 
     RI_AGHI     = 0xa70b,
     RI_AHI      = 0xa70a,
@@ -175,17 +176,27 @@ static const int tcg_target_call_oarg_regs[] = {
 
 /* signed/unsigned is handled by using COMPARE and COMPARE LOGICAL,
    respectively */
+
+#define S390_CC_EQ      8
+#define S390_CC_LT      4
+#define S390_CC_GT      2
+#define S390_CC_OV      1
+#define S390_CC_NE      (S390_CC_LT | S390_CC_GT)
+#define S390_CC_LE      (S390_CC_LT | S390_CC_EQ)
+#define S390_CC_GE      (S390_CC_GT | S390_CC_EQ)
+#define S390_CC_ALWAYS  15
+
 static const uint8_t tcg_cond_to_s390_cond[10] = {
-    [TCG_COND_EQ]  = 8,
-    [TCG_COND_LT]  = 4,
-    [TCG_COND_LTU] = 4,
-    [TCG_COND_LE]  = 8 | 4,
-    [TCG_COND_LEU] = 8 | 4,
-    [TCG_COND_GT]  = 2,
-    [TCG_COND_GTU] = 2,
-    [TCG_COND_GE]  = 8 | 2,
-    [TCG_COND_GEU] = 8 | 2,
-    [TCG_COND_NE]  = 4 | 2 | 1,
+    [TCG_COND_EQ]  = S390_CC_EQ,
+    [TCG_COND_LT]  = S390_CC_LT,
+    [TCG_COND_LTU] = S390_CC_LT,
+    [TCG_COND_LE]  = S390_CC_LE,
+    [TCG_COND_LEU] = S390_CC_LE,
+    [TCG_COND_GT]  = S390_CC_GT,
+    [TCG_COND_GTU] = S390_CC_GT,
+    [TCG_COND_GE]  = S390_CC_GE,
+    [TCG_COND_GEU] = S390_CC_GE,
+    [TCG_COND_NE]  = S390_CC_NE,
 };
 
 #ifdef CONFIG_SOFTMMU
@@ -455,6 +466,31 @@ static void tgen_setcond(TCGContext *s, TCGType type, 
TCGCond c,
     tcg_out_movi(s, type, dest, 0);
 }
 
+static void tgen_gotoi(TCGContext *s, int cc, tcg_target_long dest)
+{
+    tcg_target_long off = (dest - (tcg_target_long)s->code_ptr) >> 1;
+    if (off > -0x8000 && off < 0x7fff) {
+        tcg_out_insn(s, RI, BRC, cc, off);
+    } else if (off == (int32_t)off) {
+        tcg_out_insn(s, RIL, BRCL, cc, off);
+    } else {
+        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, dest);
+        tcg_out_insn(s, RR, BCR, cc, TCG_REG_R13);
+    }
+}
+
+static void tgen_branch(TCGContext *s, int cc, int labelno)
+{
+    TCGLabel* l = &s->labels[labelno];
+    if (l->has_value) {
+        tgen_gotoi(s, cc, l->u.value);
+    } else {
+        tcg_out16(s, RIL_BRCL | (cc << 4));
+        tcg_out_reloc(s, s->code_ptr, R_390_PC32DBL, labelno, -2);
+        s->code_ptr += 4;
+    }
+}
+
 #if defined(CONFIG_SOFTMMU)
 static void tcg_prepare_qemu_ldst(TCGContext* s, int data_reg, int addr_reg,
                                   int mem_index, int opc,
@@ -507,7 +543,7 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, int 
data_reg, int addr_reg,
     label1_ptr = (uint16_t*)s->code_ptr;
 
     /* je label1 (offset will be patched in later) */
-    tcg_out_insn(s, RI, BRC, 8, 0);
+    tcg_out_insn(s, RI, BRC, S390_CC_EQ, 0);
 
     /* call load/store helper */
 #if TARGET_LONG_BITS == 32
@@ -551,7 +587,7 @@ static void tcg_prepare_qemu_ldst(TCGContext* s, int 
data_reg, int addr_reg,
     /* jump to label2 (end) */
     *label2_ptr_p = (uint16_t*)s->code_ptr;
 
-    tcg_out_insn(s, RI, BRC, 15, 0);
+    tcg_out_insn(s, RI, BRC, S390_CC_ALWAYS, 0);
 
     /* this is label1, patch branch */
     *(label1_ptr + 1) = ((unsigned long)s->code_ptr -
@@ -734,16 +770,13 @@ static void tcg_out_qemu_st(TCGContext* s, const TCGArg* 
args, int opc)
 static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
                 const TCGArg *args, const int *const_args)
 {
-    TCGLabel* l;
     S390Opcode op;
 
     switch (opc) {
     case INDEX_op_exit_tb:
         /* return value */
         tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R2, args[0]);
-        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, (unsigned long)tb_ret_addr);
-        /* br %r13 */
-        tcg_out_insn(s, RR, BCR, 15, TCG_REG_R13);
+        tgen_gotoi(s, S390_CC_ALWAYS, (unsigned long)tb_ret_addr);
         break;
 
     case INDEX_op_goto_tb:
@@ -763,7 +796,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
             /* load address stored at s->tb_next + args[0] */
             tcg_out_ld(s, TCG_TYPE_PTR, TCG_REG_R13, TCG_REG_R13, 0);
             /* and go there */
-            tcg_out_insn(s, RR, BASR, TCG_REG_R13, TCG_REG_R13);
+            tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_R13);
         }
         s->tb_next_offset[args[0]] = s->code_ptr - s->code_buf;
         break;
@@ -971,16 +1004,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode 
opc,
         goto do_shift64;
 
     case INDEX_op_br:
-        l = &s->labels[args[0]];
-        if (l->has_value) {
-            tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, l->u.value);
-        } else {
-            /* larl %r13, ... */
-            tcg_out16(s, RIL_LARL | (TCG_REG_R13 << 4));
-            tcg_out_reloc(s, s->code_ptr, R_390_PC32DBL, args[0], -2);
-            s->code_ptr += 4;
-        }
-        tcg_out_insn(s, RR, BASR, TCG_REG_R13, TCG_REG_R13);
+        tgen_branch(s, S390_CC_ALWAYS, args[0]);
         break;
 
     case INDEX_op_brcond_i64:
@@ -989,17 +1013,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode 
opc,
     case INDEX_op_brcond_i32:
         tgen32_cmp(s, args[2], args[0], args[1]);
     do_brcond:
-        l = &s->labels[args[3]];
-        if (l->has_value) {
-            tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_R13, l->u.value);
-        } else {
-            /* larl %r13, ... */
-            tcg_out16(s, RIL_LARL | (TCG_REG_R13 << 4));
-            tcg_out_reloc(s, s->code_ptr, R_390_PC32DBL, args[3], -2);
-            s->code_ptr += 4;
-        }
-        /* bcr cond, %r13 */
-        tcg_out_insn(s, RR, BCR, tcg_cond_to_s390_cond[args[2]], TCG_REG_R13);
+        tgen_branch(s, tcg_cond_to_s390_cond[args[2]], args[3]);
         break;
 
     case INDEX_op_setcond_i32:
@@ -1194,7 +1208,7 @@ void tcg_target_qemu_prologue(TCGContext *s)
     tcg_out_insn(s, RI, AGHI, TCG_REG_R15, -160);
 
     /* br %r2 (go to TB) */
-    tcg_out_insn(s, RR, BCR, 15, TCG_REG_R2);
+    tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_R2);
 
     tb_ret_addr = s->code_ptr;
 
@@ -1202,7 +1216,7 @@ void tcg_target_qemu_prologue(TCGContext *s)
     tcg_out_insn(s, RXY, LMG, TCG_REG_R6, TCG_REG_R15, TCG_REG_R15, 208);
 
     /* br %r14 (return) */
-    tcg_out_insn(s, RR, BCR, 15, TCG_REG_R14);
+    tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_R14);
 }
 
 static inline void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val)
-- 
1.7.0.1