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Diffstat (limited to 'notes/backend.txt')
| -rw-r--r-- | notes/backend.txt | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/notes/backend.txt b/notes/backend.txt new file mode 100644 index 0000000..c93c20e --- /dev/null +++ b/notes/backend.txt @@ -0,0 +1,26 @@ +* safe&portable IR vs low-level IR + - lots of common stuff across ISAs. + - calling conventions (e.g. struct passing) can be complex and + it would be good to be able to re-use things that are common. + - some optimizations might be easier to do on the low-level IR + (and vice versa). +* register alloc can be tricky: + - division on x86 is AFAIK limited to specific regs (eax,edx?) + - loop instructions on x86 + - apparently r0 is unavailable in some insns on sh4? + - on x86_64, some regs require prefix bytes + - types: + - byte/short/int that can use parts of a reg on x86 + - int/long distinction on aarch64 + - floating point regs + - multi-reg types, typically on 32 bit arches: + - 64 bit int on i386 + - 64 bit double on MIPS? + - "special-purpose general-purpose" regs + - as above, reg for division, looping, etc. + - CHERI and pointers +* floating point + - differences across architectures? + - calling conventions + - alignment, corner cases, etc. + - also, see reg alloc |