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-rw-r--r--newasm/whitespace.s21
1 files changed, 21 insertions, 0 deletions
diff --git a/newasm/whitespace.s b/newasm/whitespace.s
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+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.type whitespace, %function
+.global whitespace
+
+// 1 unexpected char
+
+whitespace:
+ LDRB R0, [R1] // get a char
+ CMP R0, ' // space
+ BEQ 1f
+ MOVS R0, #1 // return code 1 (unexpected char)
+ BX LR
+1: ADDS R1, 1 // consume the character
+ LDRB R0, [R1] // get another character
+ CMP R0, ' // check if space
+ BEQ 1b // if so keep getting chars
+ MOVS R0, #0 // return code 0 (success)
+ BX LR