The Wasm backend targets wasm64 as the host so TCG_TARGET_REG_BITS is set to
64. Since WebAssembly instructions vary in size and can include single-byte
instructions, TCG_TARGET_INSN_UNIT_SIZE is set to 1.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 MAINTAINERS                    |  5 +++
 tcg/wasm/tcg-target-reg-bits.h | 11 ++++++
 tcg/wasm/tcg-target.h          | 61 ++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 tcg/wasm/tcg-target-reg-bits.h
 create mode 100644 tcg/wasm/tcg-target.h

V3:
- Although checkpatch.pl reports the following error in tcg/wasm/tcg-target.h,
  this file is based on the TCI code so it is preserved as-is.
  > New file 'tcg/wasm/tcg-target.h' must not have license boilerplate
  > header text, only the SPDX-License-Identifier, unless this file was
  > copied from existing code already having such text.

diff --git a/MAINTAINERS b/MAINTAINERS
index 433a44118d..89e4b51e22 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3999,6 +3999,11 @@ F: tcg/tci/
 F: tcg/tci.c
 F: disas/tci.c
 
+WebAssembly TCG target
+M: Kohei Tokunaga <ktokunaga.mail@gmail.com>
+S: Maintained
+F: tcg/wasm/
+
 Block drivers
 -------------
 VMDK
diff --git a/tcg/wasm/tcg-target-reg-bits.h b/tcg/wasm/tcg-target-reg-bits.h
new file mode 100644
index 0000000000..3dd821691f
--- /dev/null
+++ b/tcg/wasm/tcg-target-reg-bits.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef TCG_TARGET_REG_BITS_H
+#define TCG_TARGET_REG_BITS_H
+
+#if UINTPTR_MAX != UINT64_MAX
+# error Unsupported pointer size for TCG target
+#endif
+#define TCG_TARGET_REG_BITS 64
+
+#endif
diff --git a/tcg/wasm/tcg-target.h b/tcg/wasm/tcg-target.h
new file mode 100644
index 0000000000..f00761d19f
--- /dev/null
+++ b/tcg/wasm/tcg-target.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Tiny Code Generator for QEMU
+ *
+ * Based on tci/tcg-target.h
+ *
+ * Copyright (c) 2009, 2011 Stefan Weil
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef TCG_TARGET_H
+#define TCG_TARGET_H
+
+#define TCG_TARGET_INSN_UNIT_SIZE 1
+#define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
+
+/* Number of registers available. */
+#define TCG_TARGET_NB_REGS 16
+
+/* List of registers which are used by TCG. */
+typedef enum {
+    TCG_REG_R0 = 0,
+    TCG_REG_R1,
+    TCG_REG_R2,
+    TCG_REG_R3,
+    TCG_REG_R4,
+    TCG_REG_R5,
+    TCG_REG_R6,
+    TCG_REG_R7,
+    TCG_REG_R8,
+    TCG_REG_R9,
+    TCG_REG_R10,
+    TCG_REG_R11,
+    TCG_REG_R12,
+    TCG_REG_R13,
+    TCG_REG_R14,
+    TCG_REG_R15,
+
+    TCG_REG_TMP = TCG_REG_R13,
+    TCG_AREG0 = TCG_REG_R14,
+    TCG_REG_CALL_STACK = TCG_REG_R15,
+} TCGReg;
+
+#endif /* TCG_TARGET_H */
-- 
2.43.0