65 lines
1.2 KiB
Python
65 lines
1.2 KiB
Python
# This tests small int range for 32-bit machine
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# Small ints are variable-length encoded in MicroPython, so first
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# test that encoding works as expected.
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print(0)
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print(1)
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print(-1)
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# Value is split in 7-bit "subwords", and taking into account that all
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# ints in Python are signed, there're 6 bits of magnitude. So, around 2^6
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# there's "turning point"
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print(63)
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print(64)
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print(65)
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print(-63)
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print(-64)
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print(-65)
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# Maximum values of small ints on 32-bit platform
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print(1073741823)
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# Per python semantics, lexical integer is without a sign (i.e. positive)
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# and '-' is unary minus operation applied to it. That's why -1073741824
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# (min two-complement's negative value) is not allowed.
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print(-1073741823)
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# Operations tests
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a = 0x3fffff
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print(a)
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a *= 0x10
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print(a)
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a *= 0x10
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print(a)
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a += 0xff
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print(a)
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# This would overflow
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#a += 1
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a = -0x3fffff
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print(a)
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a *= 0x10
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print(a)
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a *= 0x10
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print(a)
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a -= 0xff
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print(a)
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# This still doesn't overflow
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a -= 1
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print(a)
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# This would overflow
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#a -= 1
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# Shifts to big amounts are undefined behavior in C and is CPU-specific
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# These are compile-time constexprs
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print(1 >> 32)
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print(1 >> 64)
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print(1 >> 128)
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# These are runtime calcs
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a = 1
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print(a >> 32)
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print(a >> 64)
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print(a >> 128)
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