ia32: Add and use ia32_is_8bit_val().

ir/be/ia32/bearch_ia32_t.h

@@ -129,4 +129,9 @@ void ia32_adjust_pic(ir_graph *irg);
 
 ir_node *ia32_get_pic_base(ir_graph *irg);
 
+static inline bool ia32_is_8bit_val(int32_t const v)
+{
+	return -128 <= v && v < 128;
+}
+
 #endif

ir/be/ia32/ia32_common_transform.c

@@ -37,13 +37,13 @@ static bool check_immediate_constraint(long val, char immediate_constraint_type)
 	case 'i':
 	case 'n': return true;
 
-	case 'I': return    0 <= val && val <=  31;
-	case 'J': return    0 <= val && val <=  63;
-	case 'K': return -128 <= val && val <= 127;
+	case 'I': return 0 <= val && val <=  31;
+	case 'J': return 0 <= val && val <=  63;
+	case 'K': return ia32_is_8bit_val(val);
 	case 'L': return val == 0xff || val == 0xffff;
-	case 'M': return    0 <= val && val <=   3;
-	case 'N': return    0 <= val && val <= 255;
-	case 'O': return    0 <= val && val <= 127;
+	case 'M': return 0 <= val && val <=   3;
+	case 'N': return 0 <= val && val <= 255;
+	case 'O': return 0 <= val && val <= 127;
 
 	default: panic("Invalid immediate constraint found");
 	}

ir/be/ia32/ia32_emitter.c

@@ -1920,7 +1920,7 @@ static void bemit_modrm8(reg_modifier_t high_part, const arch_register_t *reg)
  */
 static unsigned get_signed_imm_size(int offset)
 {
-	if (-128 <= offset && offset < 128) {
+	if (ia32_is_8bit_val(offset)) {
 		return 1;
 	} else if (-32768 <= offset && offset < 32768) {
 		return 2;
@@ -1956,7 +1956,7 @@ static void bemit_mod_am(unsigned reg, const ir_node *node)
 	} else if (offs == 0) {
 		modrm |= MOD_IND;
 		emitoffs = 0;
-	} else if (-128 <= offs && offs < 128) {
+	} else if (ia32_is_8bit_val(offs)) {
 		modrm |= MOD_IND_BYTE_OFS;
 		emitoffs = 8;
 	} else {