jscript: Added new jmp_z opcode, more appropriate for branches.

dlls/jscript/compile.c

@@ -915,7 +915,7 @@ static HRESULT compile_if_statement(compiler_ctx_t *ctx, if_statement_t *stat)
     if(FAILED(hres))
         return hres;
 
-    jmp_else = push_instr(ctx, OP_cnd_z);
+    jmp_else = push_instr(ctx, OP_jmp_z);
     if(jmp_else == -1)
         return E_OUTOFMEMORY;
 
@@ -929,9 +929,6 @@ static HRESULT compile_if_statement(compiler_ctx_t *ctx, if_statement_t *stat)
 
     instr_ptr(ctx, jmp_else)->arg1.uint = ctx->code_off;
 
-    if(push_instr(ctx, OP_pop) == -1)
-        return E_OUTOFMEMORY;
-
     if(stat->else_stat) {
         hres = compile_statement(ctx, stat->else_stat);
         if(FAILED(hres))

dlls/jscript/engine.c

@@ -2884,6 +2884,28 @@ static HRESULT interp_jmp(exec_ctx_t *ctx)
     return S_OK;
 }
 
+static HRESULT interp_jmp_z(exec_ctx_t *ctx)
+{
+    const unsigned arg = ctx->parser->code->instrs[ctx->ip].arg1.uint;
+    VARIANT_BOOL b;
+    VARIANT *v;
+    HRESULT hres;
+
+    TRACE("\n");
+
+    v = stack_pop(ctx);
+    hres = to_boolean(v, &b);
+    VariantClear(v);
+    if(FAILED(hres))
+        return hres;
+
+    if(b)
+        ctx->ip++;
+    else
+        ctx->ip = arg;
+    return S_OK;
+}
+
 static HRESULT interp_pop(exec_ctx_t *ctx)
 {
     TRACE("\n");

dlls/jscript/engine.h

@@ -69,6 +69,7 @@ typedef struct _func_stack {
     X(instanceof, 1, 0,0)                  \
     X(int,        1, ARG_INT,    0)        \
     X(jmp,        0, ARG_ADDR,   0)        \
+    X(jmp_z,      0, ARG_ADDR,   0)        \
     X(lshift,     1, 0,0)                  \
     X(lt,         1, 0,0)                  \
     X(lteq,       1, 0,0)                  \