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Instead of defining all the registers as implicit defs, add the RegisterMask operand to Calls to pass the call-preserved registers to the compiler. This works around the LLVM limitation of having a max of 255 implicit defs per instruction. Therefore, now our machines can again have large number of registers.
This reverts commit 5688802. Now that the backend generation is fixed to work with larger number of register, re-enable the testing with a bigger machine.
pjaaskel
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Feb 2, 2026
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Thanks. Can you add a test that specifically tests calls when there are more than 256 regs?
This tests call's regmask operand. Vararray generates one call with fp and one without.
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Added huge.adf to Scheduler tests vararray.c test. It has lots of registers, and the vararray.c generates one call that uses framepointer, and one without so it seems appropriate: This test with huge.adf fails before this patch, and works now. |
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Instead of defining all the registers as implicit defs, add the RegisterMask operand to Calls to pass the call-preserved registers to the compiler.
This works around the LLVM limitation of having a max of 255 implicit defs per instruction. Therefore, now our machines can again have larger number of registers.
Fixes #300