Further clarify treatment of bitfields in the floating-point calling convention #100
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…convention This patch reflects the observed behaviour from GCC, as discussed in issue riscv-non-isa#99. Fixes riscv-non-isa#99.
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aswaterman
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I agree this might not be the best technical solution, but simply documenting what the GCC port happens to do here still seems preferable to me.
jim-wilson
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This looks like a correct description of how gcc is implementing this.
jrtc27
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| Zero-size bitfields are not ignored, so `struct { float f; int64_t i : 32; int | ||
| 0;`} would be passed according to the integer calling convention. |
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Hm, actually, #99 (comment) suggests GCC has since changed ABI for zero-size bitfields, meaning I think this sentence (and the diff above to add a special special case on top of the special case) should go. @jim-wilson do you agree?
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I think this is redundant now that GCC's was updated to fix the corner-case around zero-size bitfields and floating point values. Does anyone disagree? |
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This patch reflects the observed behaviour from GCC, as discussed in
issue #99.
Note: this is a solution to #99 but not necessarily the best one (see my comment in that thread). Alternatively, we could always ignore zero-width bitfields when considering eligibility for passing according to the floating point calling convention which seems more consistent even if it doesn't fully match what GCC currently does.