Peter Trommler [Tue, 7 Nov 2023 20:47:24 +0000 (21:47 +0100)]
[PATCH] PPC NCG: Generate clear right insn at arch width
The clear right immediate (clrrxi) is only available in word and
doubleword width. Generate clrrxi instructions at architecture
width for all MachOp widths.
Previously `ghc-prim`'s atomic wrappers used the legacy `__sync_*`
family of C builtins. Here we refactor these to rather use the
appropriate C11 atomic equivalents, allowing us to be more explicit
about the expected ordering semantics.
GHC 8.10 fails to build on armel with the following error:
LLVM ERROR: unable to allocate function argument #8
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0. Program arguments: llc-12 -O2 -enable-tbaa -relocation-model=pic -mcpu=arm7tdmi -mattr=+soft-float,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-fp16,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fullfp16,-fp64,-d32,-neon,-crypto,-dotprod,-fp16fml,-bf16,-mve,-mve.fp,-fpregs,+strict-align /tmp/ghc5537_0/ghc_6.bc -o /tmp/ghc5537_0/ghc_7.lm_s
1. Running pass 'Function Pass Manager' on module '/tmp/ghc20177_0/ghc_6.bc'.
2. Running pass 'ARM Instruction Selection' on function '@"stg_gc_f1$def"'
`llc-12' failed in phase `LLVM Compiler'. (Exit code: -6)
make[3]: *** [rts/ghc.mk:325: rts/dist/build/HeapStackCheck.o] Error 1
This patch enables a few native 64-bit integer instructions
on x32 which are available on this architecture despite using
32-bit pointers. These instructions are present on x86_64 but
not on x86 and ghc checks the size of (void *) to determine
that. This method fails on x32 since despite using 32-bit
pointers and hence sizeof(void *) == 4, it still uses the
full x86_64 instruction set and software-emulated variants
of the aforementioned 64-bit integer instructions are
therefore not present in the toolchain which will make ghc
fail to build on x32.
See: https://ghc.haskell.org/trac/ghc/ticket/11571
Jani writes: The D16 part was Debian/Ubuntu specific, IIRC we define hardfloat
in that particular variant (16 double registers) or we had a different naming
for some reason.