Fix sign-extension of 64-bit literals #213
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When SUPPORT_64_BIT_LITERALS is not enabled, INTEGER nodes store the negation of the integer value. This is done to support the full range of 32-bit signed integers, since the positive value 2147483648 cannot be represented as a positive signed 32-bit integer. To get the actual value, it must be negated. If the negated value is -2147483648, negating it produces 2147483648, which overflows the 32-bit signed integer range (assuming the host platform uses 32-bit integers) and loops back to -2147483648. Additionally, for 64-bit targets, the value must be sign-extended to 64-bits, which is done by left shifting by 31. On platforms with 32-bit integers, the two's complement representation of 2147483648 is the same as -2147483648's two's complement, 0x80000000 in hex, and so everything works out. On platforms with larger integers, such as some shells, the value 2147483648 is representable as a positive integer, and so negating -2147483648 produces 2147483648, which produces an invalid sign-extended value when shifted. Sign-extension is only performed when targeting 64-bit platforms, where 2147483648 >> 31 evaluates to 1.
laurenthuberdeau
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Nov 11, 2025
Without this, the 0x80000000 literal in sign-extended which causes differences in the bootstrapped compiler binaries. See #213 for more information.
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Context
When
SUPPORT_64_BIT_LITERALSis not enabled,INTEGERnodes store the negation of the integer value. This is done to support the full range of 32-bit signed integers, since the positive value2147483648cannot be represented as a positive signed 32-bit integer.To get the actual value, it must be negated. If the negated value is
-2147483648, negating it produces2147483648, which overflows the 32-bit signed integer range (assuming the host platform uses 32-bit integers) and loops back to-2147483648. Additionally, for 64-bit targets, the value must be sign-extended to 64-bits, which is done by left shifting by 31.On platforms with 32-bit integers, the two's complement representation of 2147483648 is the same as -2147483648's two's complement, 0x80000000 in hex, and so everything works out.
On platforms with larger integers, such as some shells, the value
2147483648is representable as a positive integer, and so negating-2147483648produces2147483648, which produces an invalid sign-extended value when shifted. Sign-extension is only performed when targeting 64-bit platforms, where2147483648 >> 31evaluates to 1.This PR changes the sign-extension to no longer assume exactly 32-bit integers.