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It's been 32 ever since the CRIS port was committed. A TODO-item of mine has been to check whether the non-default setting of MAX_FIXED_MODE_SIZE makes sense wrt. performance and/or code-size with a modern gcc. It doesn't, so it goes. The setting is now the default, GET_MODE_BITSIZE (DImode) (defaults.h) i.e. 64. Measurements at r11-7500 (f3641ac70eb0) on coremark with "-O2 -march=v10 -mno-mul-bug-workaround" shows 0.04% performance improvement with this change, and by inspection the effect is that unused and/or unneeded stack-frames are eliminated more often in the floating-point library (not in the coremark main loop, thus the marginal improvement). The floating-point library is full of 64-bit unions used to pick apart floating point numbers, so this kind of makes sense. Inspection of a simulator trace shows that this is indeed the only effect in coremark. Other local micro-benchmarks agree as to the net effect (no traces were inspected though), and the most floating-point-heavy test shows an 8% improvement. These effects are of course subject to gcc core tweaks and may make sense to be adjusted again in a future release. While MAX_FIXED_MODE_SIZE is IMO supposed to be an optional macro for performance, setting it to anything smaller than twice the size of an address exposes bad decisions in gcc middle end, sometimes leading to internal compiler errors. (It being set to 32 should *not* affect use of DImode as an integer mode; it's for "integer machine modes of this size or smaller can be used for structures and unions with the appropriate sizes".) Thus, with the default 64 instead of 32, there are two tests that now pass for the first time: gcc.dg/attr-vector_size.c and gcc.dg/tree-ssa/pr93121-1.c. gcc: * config/cris/cris.h (MAX_FIXED_MODE_SIZE): Don't define.
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