JIT/AArch64: Use 'shifted register' if available (#7108)

One shift instruction can be saved if 'shifted register' is used.

It's worth noting that the destination register of previous shift
instruction doesn't hold the shift result any longer now. And we have to
guarantee that 'shifted register' mode is applied to all the use sites
of this destination register.

Besides, several code-style issues are fixed.

Change-Id: I8bcdd092253d342d383732a926512e761e453808

Author: shqking

ext/opcache/jit/zend_jit_arm64.dasc

@@ -1894,7 +1894,7 @@ static int zend_jit_icall_throw_stub(dasm_State **Dst)
 	|	ldr IP, EX->opline
 	|	// if (EX(opline)->opcode != ZEND_HANDLE_EXCEPTION) {
 	|	ldrb TMP1w, OP:IP->opcode
-	|	cmp TMP1w,# ZEND_HANDLE_EXCEPTION
+	|	cmp TMP1w, #ZEND_HANDLE_EXCEPTION
 	|	beq >1
 	|	// EG(opline_before_exception) = opline;
 	|	MEM_STORE_64_ZTS str, IP, executor_globals, opline_before_exception, TMP2
@@ -2227,8 +2227,7 @@ static int zend_jit_hybrid_hot_counter_stub(dasm_State **Dst, uint32_t cost)
 	|	sub REG2, REG2, TMP1
 	|	// divide by sizeof(zend_op)
 	||	ZEND_ASSERT(sizeof(zend_op) == 32);
-	|	asr REG2, REG2, #2
-	|	add TMP1, REG1, REG2
+	|	add TMP1, REG1, REG2, asr #2
 	|	ldr TMP1, [TMP1, #offsetof(zend_jit_op_array_hot_extension, orig_handlers)]
 	|	br TMP1
 	return 1;
@@ -2696,7 +2695,7 @@ static int zend_jit_unwind_cb(_Unwind_Context *ctx, void *a)
 	if (arg->cnt == 3) {
 		return 5; // _URC_END_OF_STACK
 	}
-	return 0; // _URC_NO_REASON;
+	return 0;     // _URC_NO_REASON;
 }
 
 static void ZEND_FASTCALL zend_jit_touch_vm_stack_data(void *vm_stack_data)
@@ -3975,8 +3974,6 @@ static int zend_jit_math_long_long(dasm_State    **Dst,
 			/* Use 'smulh' to get the upper 64 bits fo the 128-bit result.
 			 * For signed multiplication, the top 65 bits of the result will contain
 			 * either all zeros or all ones if no overflow occurred.
-			 * Note that 'cmp, TMP1, Rx(result_reg), asr, #63' is not supported by DynASM/arm64
-			 * currently, and we put 'asr' and 'cmp' separately.
 			 * Flag: bne -> overflow. beq -> no overflow.
 			 */
 			use_ovf_flag = 0;
@@ -10024,9 +10021,8 @@ static int zend_jit_defined(dasm_State **Dst, const zend_op *opline, zend_uchar
 	|.cold_code
 	|4:
 	|	MEM_LOAD_64_ZTS ldr, FCARG1x, executor_globals, zend_constants, FCARG1x
-	|	lsr REG0, REG0, #1
 	|	ldr TMP1w, [FCARG1x, #offsetof(HashTable, nNumOfElements)]
-	|	cmp TMP1, REG0
+	|	cmp TMP1, REG0, lsr #1
 
 	if (smart_branch_opcode) {
 		if (exit_addr) {