1 files changed, 39 insertions, 0 deletions
diff --git a/CSAPP/chap2/shifts.c b/CSAPP/chap2/shifts.c
new file mode 100644
index 0000000..836476d
--- /dev/null
+++ b/CSAPP/chap2/shifts.c
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+/*
+ * Shift operations
+ *
+ * Right shifts might use either arithmetic shifts or logical shifts.
+ *
+ * This small piece of code should identify which one is used
+ */
+
+#include <stdio.h>
+
+int main(void)
+{
+	/* Using char so we care for a single byte only */
+	char x, a;
+	unsigned char y, b;
+	/* bin 10101001 */
+	a = b = 0xA9;
+
+	printf("Original signed variable: 0x%.2x\n", a);
+
+	/*
+	 * Signed data variables are right shifted using Arithmetic shift. i.e.
+	 * left bits are filled with a copy of the most significant bit of the
+	 * original value
+	 */
+	x = a >> 3;
+	printf("Signed right shift by 3: 0x%.2x\n\n", x);
+
+	printf("Original unsigned variable: 0x%.2x\n", b);
+	/*
+	 * Unsigned data variables are right shifted logically. i.e. left bits
+	 * are just filled with zeros
+	 */
+	y = b >> 3;
+	printf("Unsigned right shift by 3: 0x%.2x\n", y);
+	return 0;
+}
+
+