[PATCH v4 19/30] tcg/loongarch64: Implement br/brcond ops

From: WANG Xuerui <git@xen0n.name>
To: qemu-devel@nongnu.org
Cc: "WANG Xuerui" <git@xen0n.name>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"Laurent Vivier" <laurent@vivier.eu>
Subject: [PATCH v4 19/30] tcg/loongarch64: Implement br/brcond ops
Date: Fri, 24 Sep 2021 00:59:28 +0800	[thread overview]
Message-ID: <20210923165939.729081-20-git@xen0n.name> (raw)
In-Reply-To: <20210923165939.729081-1-git@xen0n.name>

Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-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 a92f50b165..f081388d2d 100644
--- a/tcg/loongarch64/tcg-target.c.inc
+++ b/tcg/loongarch64/tcg-target.c.inc
@@ -408,6 +408,44 @@ 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
  */
@@ -430,6 +468,17 @@ 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);
@@ -753,6 +802,10 @@ 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:
-- 
2.33.0


