Fix SHRU16 for constant value

Author: boriel

src/arch/zx48k/backend/__16bit.py

@@ -886,6 +886,9 @@ def _shru16(ins):
         Shift Right Arithmetic
     """
     op1, op2 = tuple(ins.quad[2:])
+    label = tmp_label()
+    label2 = tmp_label()
+
     if is_int(op2):
         op = int16(op2)
         if op == 0:
@@ -903,11 +906,9 @@ def _shru16(ins):
         output = _8bit_oper(op2)
         output.append('ld b, a')
         output.extend(_16bit_oper(op1))
+        output.append('or a')
+        output.append('jr z, %s' % label2)
 
-    label = tmp_label()
-    label2 = tmp_label()
-    output.append('or a')
-    output.append('jr z, %s' % label2)
     output.append('%s:' % label)
     output.append('srl h')
     output.append('rr l')

tests/functional/opt1_shiftu16_const.asm

@@ -0,0 +1,50 @@
+	org 32768
+.core.__START_PROGRAM:
+	di
+	push ix
+	push iy
+	exx
+	push hl
+	exx
+	ld hl, 0
+	add hl, sp
+	ld (.core.__CALL_BACK__), hl
+	ei
+	jp .core.__MAIN_PROGRAM__
+.core.__CALL_BACK__:
+	DEFW 0
+.core.ZXBASIC_USER_DATA:
+	; Defines USER DATA Length in bytes
+.core.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_END - .core.ZXBASIC_USER_DATA
+	.core.__LABEL__.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_LEN
+	.core.__LABEL__.ZXBASIC_USER_DATA EQU .core.ZXBASIC_USER_DATA
+_num1:
+	DEFB 00, 00
+_num2:
+	DEFB 00, 00
+.core.ZXBASIC_USER_DATA_END:
+.core.__MAIN_PROGRAM__:
+	ld hl, (_num1)
+	ld b, 3
+.LABEL.__LABEL0:
+	srl h
+	rr l
+	djnz .LABEL.__LABEL0
+.LABEL.__LABEL1:
+	ld (_num2), hl
+	ld hl, 0
+	ld b, h
+	ld c, l
+.core.__END_PROGRAM:
+	di
+	ld hl, (.core.__CALL_BACK__)
+	ld sp, hl
+	exx
+	pop hl
+	exx
+	pop iy
+	pop ix
+	ei
+	ret
+	;; --- end of user code ---
+	END

tests/functional/opt1_shiftu16_const.bas

@@ -0,0 +1,3 @@
+dim num1, num2 as uinteger
+num2 = num1 >> 3
+