Pdp11-aout: Remove invalid conversion and restore build
This patch fixes a build error when cross-compiling GCC for pdp11-aout by correcting a type mismatch.
When cross-compiling GCC for the pdp11-aout target, a recent change introduced a build failure due to an invalid conversion from int* to unsigned int*. This patch addresses the issue by changing the type of the variable in pdp11_conditional_register_usage from int to unsigned int, restoring the build functionality for this specific target.
In Details
The pdp11-aout port of GCC's backend (gcc/config/pdp11/pdp11.cc) encountered a type mismatch in the pdp11_conditional_register_usage function. This function likely deals with the specific register allocation or usage conventions for the PDP-11 architecture. The fix involves correcting a pointer type to resolve a build-time error related to implicit conversions, ensuring the AOUT object file format generation for PDP-11 remains consistent.
For Context
Compilers like GCC translate human-readable code into machine instructions. This process is complex and often involves specific configurations for different computer architectures and operating systems, known as 'targets'. When GCC is compiled to run on one system but generate code for a different system (called 'cross-compiling'), it needs to understand the target's unique characteristics. This commit addresses a situation where GCC was failing to build itself for a specific, older target (pdp11-aout, referring to the PDP-11 computer architecture and the AOUT executable format). The problem was a type mismatch in the compiler's internal code, where an int pointer was being incorrectly converted to an unsigned int pointer, leading to a build error. This fix simply corrects that type, allowing the cross-compilation process for pdp11-aout to complete successfully.