[PULL 19/31] tcg/loongarch64: Implement br/brcond ops

[Richard Henderson]

From: WANG Xuerui <git@xen0n.name>

Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211221054105.178795-20-git@xen0n.name>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/loongarch64/tcg-target-con-set.h |  1 +
 tcg/loongarch64/tcg-target.c.inc     | 53 ++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/tcg/loongarch64/tcg-target-con-set.h 
b/tcg/loongarch64/tcg-target-con-set.h
index fb56f3a295..367689c2e2 100644
--- a/tcg/loongarch64/tcg-target-con-set.h
+++ b/tcg/loongarch64/tcg-target-con-set.h
@@ -15,6 +15,7 @@
  * tcg-target-con-str.h; the constraint combination is inclusive or.
  */
 C_O0_I1(r)
+C_O0_I2(rZ, rZ)
 C_O1_I1(r, r)
 C_O1_I2(r, r, rC)
 C_O1_I2(r, r, ri)
diff --git a/tcg/loongarch64/tcg-target.c.inc b/tcg/loongarch64/tcg-target.c.inc
index 0ae193fba5..aedfc0df84 100644
--- a/tcg/loongarch64/tcg-target.c.inc
+++ b/tcg/loongarch64/tcg-target.c.inc
@@ -434,6 +434,44 @@ static void tcg_out_clzctz(TCGContext *s, LoongArchInsn 
opc,
     tcg_out_opc_or(s, a0, TCG_REG_TMP0, a0);
 }
 
+/*
+ * Branch helpers
+ */
+
+static const struct {
+    LoongArchInsn op;
+    bool swap;
+} tcg_brcond_to_loongarch[] = {
+    [TCG_COND_EQ] =  { OPC_BEQ,  false },
+    [TCG_COND_NE] =  { OPC_BNE,  false },
+    [TCG_COND_LT] =  { OPC_BGT,  true  },
+    [TCG_COND_GE] =  { OPC_BLE,  true  },
+    [TCG_COND_LE] =  { OPC_BLE,  false },
+    [TCG_COND_GT] =  { OPC_BGT,  false },
+    [TCG_COND_LTU] = { OPC_BGTU, true  },
+    [TCG_COND_GEU] = { OPC_BLEU, true  },
+    [TCG_COND_LEU] = { OPC_BLEU, false },
+    [TCG_COND_GTU] = { OPC_BGTU, false }
+};
+
+static void tcg_out_brcond(TCGContext *s, TCGCond cond, TCGReg arg1,
+                           TCGReg arg2, TCGLabel *l)
+{
+    LoongArchInsn op = tcg_brcond_to_loongarch[cond].op;
+
+    tcg_debug_assert(op != 0);
+
+    if (tcg_brcond_to_loongarch[cond].swap) {
+        TCGReg t = arg1;
+        arg1 = arg2;
+        arg2 = t;
+    }
+
+    /* all conditional branch insns belong to DJSk16-format */
+    tcg_out_reloc(s, s->code_ptr, R_LOONGARCH_BR_SK16, l, 0);
+    tcg_out32(s, encode_djsk16_insn(op, arg1, arg2, 0));
+}
+
 /*
  * Entry-points
  */
@@ -456,6 +494,17 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_opc_jirl(s, TCG_REG_ZERO, a0, 0);
         break;
 
+    case INDEX_op_br:
+        tcg_out_reloc(s, s->code_ptr, R_LOONGARCH_BR_SD10K16, arg_label(a0),
+                      0);
+        tcg_out_opc_b(s, 0);
+        break;
+
+    case INDEX_op_brcond_i32:
+    case INDEX_op_brcond_i64:
+        tcg_out_brcond(s, a2, a0, a1, arg_label(args[3]));
+        break;
+
     case INDEX_op_ext8s_i32:
     case INDEX_op_ext8s_i64:
         tcg_out_ext8s(s, a0, a1);
@@ -779,6 +828,10 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode 
op)
     case INDEX_op_goto_ptr:
         return C_O0_I1(r);
 
+    case INDEX_op_brcond_i32:
+    case INDEX_op_brcond_i64:
+        return C_O0_I2(rZ, rZ);
+
     case INDEX_op_ext8s_i32:
     case INDEX_op_ext8s_i64:
     case INDEX_op_ext8u_i32:
-- 
2.25.1