add translation of br_if instruction

8 files changed, 77 insertions, 4 deletions

diff --git a/tests/wasm_compile_br_if/Makefile b/tests/wasm_compile_br_if/Makefile
new file mode 120000
index 0000000..e451c8b
--- /dev/null
+++ b/tests/wasm_compile_br_if/Makefile
@@ -0,0 +1 @@
+../wasm_compile_simple_module/Makefile
\ No newline at end of file
diff --git a/tests/wasm_compile_br_if/instructions.wat b/tests/wasm_compile_br_if/instructions.wat
new file mode 100644
index 0000000..506a462
--- /dev/null
+++ b/tests/wasm_compile_br_if/instructions.wat
@@ -0,0 +1,27 @@
+;;; this test is loosely based on wasm_compile_br
+(module
+ (memory 0 1)
+ ;; this function returns -1 if its argument is 10 or 11 and 0 otherwise
+ (func $eq10or11 (param $x i32) (result i32)
+       (if (result i32)
+	   (i32.sub
+	    (get_local $x)
+	    (i32.const 10))
+	 (then
+	  (br_if 0 (i32.add (i32.const -3) (i32.const 3))
+		 (i32.sub (get_local $x) (i32.const 11)))
+	  (i32.const 1)
+	  (i32.sub))
+	 (else
+	  (i32.const -1))))
+ (func $main
+       ;; write 0x00000000 at MEMORY_BOTTOM_ADDR
+       (i32.store offset=0x0 align=2 (i32.const 0x0)
+		  (call $eq10or11 (i32.const 12)))
+       ;; write 0xFFFFFFFF at MEMORY_BOTTOM_ADDR + 0x4
+       (i32.store offset=0x0 align=2 (i32.const 0x4)
+		  (call $eq10or11 (i32.const 10)))
+       ;; write 0xFFFFFFFF at MEMORY_BOTTOM_ADDR + 0x8
+       (i32.store offset=0x0 align=2 (i32.const 0x8)
+		  (call $eq10or11 (i32.const 11))))
+ (export "main" (func $main)))
diff --git a/tests/wasm_compile_br_if/test.v b/tests/wasm_compile_br_if/test.v
new file mode 120000
index 0000000..f0235d8
--- /dev/null
+++ b/tests/wasm_compile_br_if/test.v
@@ -0,0 +1 @@
+../wasm_compile_simple_module/test.v
\ No newline at end of file
diff --git a/tests/wasm_compile_br_if/words_to_verify.mem b/tests/wasm_compile_br_if/words_to_verify.mem
new file mode 100644
index 0000000..aac1103
--- /dev/null
+++ b/tests/wasm_compile_br_if/words_to_verify.mem
@@ -0,0 +1,6 @@
+// address  value
+   0FFFFC   23
+
+   200	    00000000
+   204	    FFFFFFFF
+   208	    FFFFFFFF
diff --git a/tests/wasm_compile_simple_module/test.v b/tests/wasm_compile_simple_module/test.v
index 80f5590..5e28ba1 100644
--- a/tests/wasm_compile_simple_module/test.v
+++ b/tests/wasm_compile_simple_module/test.v
@@ -159,7 +159,7 @@ module wasm_compile_test();
       CLK <= 0;
       RST <= 1;
 
-      for (i = 0; i < 5000; i++) begin
+      for (i = 0; i < 10000; i++) begin
 	 #1;
 
 	 CLK <= ~CLK;
@@ -194,9 +194,9 @@ module wasm_compile_test();
 
 	    $finish;
 	 end // if (M_finished)
-      end // for (i = 0; i < 5000; i++)
+      end // for (i = 0; i < 10000; i++)
 
-      $display("error: cpu hasn't finished its operations in 2500 ticks");
+      $display("error: cpu hasn't finished its operations in 5000 ticks");
       $finish;
    end // initial begin
 endmodule // stack_machine_test
diff --git a/tools/translate.c b/tools/translate.c
index 64ed407..8b28aad 100644
--- a/tools/translate.c
+++ b/tools/translate.c
@@ -426,6 +426,42 @@ fail:
 	return -1;
 }
 
+static int _translate_br_if(struct translation *data)
+{
+	struct target *br_end;
+	struct instruction **expr = &data->function->translated_body;
+	struct types *backed_stack = NULL;
+	int retval = -1;
+
+	br_end = add_target(data->module);
+
+	if (!br_end)
+		goto fail;
+
+	if (i_cond_jump_n(ptr_after(&br_end->instr), expr))
+		goto fail;
+
+	backed_stack = data->types_stack;
+	get_type(backed_stack);
+
+	if (_translate_br(data))
+		goto fail;
+
+	br_end->instr = data->function->translated_body->prev;
+	retval = 0;
+
+fail:
+	if (backed_stack) {
+		put_type(data->types_stack);
+		data->types_stack = backed_stack;
+	}
+
+	if (retval)
+		PRERR("Couldn't translate br_if instruction\n");
+
+	return retval;
+}
+
 static int _translate_call(struct translation *data)
 {
 	uint32_t funcidx;
diff --git a/tools/translate_xmacro.h b/tools/translate_xmacro.h
index f68f317..958d8d9 100644
--- a/tools/translate_xmacro.h
+++ b/tools/translate_xmacro.h
@@ -16,11 +16,12 @@ TLS(WASM_I32_STORE8,   storeb_p,            i32_i32,        empty)
 TLS(WASM_I32_STORE16,  storew_p,            i32_i32,        empty)
 
 /*
- * There are more checks to be performed in case of if, but we do them
+ * There are more checks to be performed in case of if and br_if, but we do them
  * another way and only check for the i32 condition value here.
  */
 TC (WASM_IF,           if,                  i32,            custom)
 TC (WASM_BR,           br,                  custom,         custom)
+TC (WASM_BR_IF,        br_if,               i32,            custom)
 TC (WASM_CALL,         call,                custom,         custom)
 TC (WASM_LOCAL_GET,    local_get,           empty,          custom)
 TC (WASM_I32_CONST,    const,               empty,          i32)
diff --git a/tools/wasm.h b/tools/wasm.h
index 0c36c11..476f892 100644
--- a/tools/wasm.h
+++ b/tools/wasm.h
@@ -26,6 +26,7 @@
 #define WASM_ELSE          0x05
 #define WASM_END           0x0B
 #define WASM_BR            0x0C
+#define WASM_BR_IF         0x0D
 #define WASM_CALL          0x10
 
 #define WASM_LOCAL_GET     0x20