Odin/tests/issues/test_issue_6809_6816.c

#include <stdint.h>
#include <stdbool.h>

// Clang compiles this to a single 32-bit register comparison:
//     cmp w0, #-1
// If the caller failed to sign-extend the 8-bit -1 (0xFF) to 32-bit (0xFFFFFFFF),
// the comparison fails.
bool test_i8(int8_t val) {
    return val == -1;
}

// Clang compiles this to:
//     cmp w0, #200
// If the caller did not zero-extend 200 (0xC8) to 32-bit, leaving garbage
// in the upper bits of w0, this comparison fails.
bool test_u8(uint8_t val) {
    return val == 200;
}

// Clang compiles this to:
//     cmp w0, #1
// If the caller did not zero-extend the boolean true (1) to 32-bit,
// leaving garbage in the upper bits of w0, this comparison fails.
bool test_bool(bool val) {
    return val == true;
}