[arm][compiler-rt] add armv8m.main and arv8.1m.main targets

[stuij]

Summary

These changes were enough to compile compiler-rt builtins for armv8m.main and
armv8.1m.main.

[peter.smith]

From an ELF perspective this looks good to me, armv7e-m appears in the same places for these targets. Will be worth adding someone from Apple to see if it is worth adding to CompilerRTDarwinUtils.cmake.

compiler-rt/lib/builtins/CMakeLists.txt

564

in cmake/Modules/CompilerRTDarwinUtils.cmake there are a few references to macho_embedded_ARCHS for example:

set(DARWIN_macho_embedded_ARCHS armv6m armv7m armv7em armv7 i386 x86_64)

Would be useful to get someone from Apple on the review to check if we should add to this list as well. My guess is that these aren't needed for building bare-metal ELF.

[stuij]

Hi @beanz . @peter.smith wondered if it would be useful to add armv8 targets to DARWIN_macho_embedded_ARCHS or somewhere else. Do you have an opinion on this, or could you recommend someone else who might have?

Thanks!

[stuij]

It's now been a bit more than a week since the last reply. I suggest we merge this. If we want to add the architectures to the Apple-specific targets, that can always be done later.

[peter.smith]

In D99600#2688737, @stuij wrote:

It's now been a bit more than a week since the last reply. I suggest we merge this. If we want to add the architectures to the Apple-specific targets, that can always be done later.

Sounds reasonable to me.

[beanz]

Sorry for not seeing this. Ignoring macho_embedded is the right call. That is really just used for macho baremetal and not many people outside Apple would bother with it.

[stuij]

Ok, thanks for the confirmation @beanz.

Is someone willing to accept the revision?

[peter.smith]

LGTM, sorry for the delay.

[stuij]

np, thanks so much!

compiler-rt/cmake/builtin-config-ix.cmake

 
 builtin_check_c_compiler_source(COMPILER_RT_HAS_ASM_LSE
 "
 asm(\".arch armv8-a+lse\");
 asm(\"cas w0, w1, [x2]\");
 ")
 
 set(ARM64 aarch64)
-set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k)
+set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv8m.main armv8.1m.main)
 set(HEXAGON hexagon)
 set(X86 i386)
 set(X86_64 x86_64)
 set(MIPS32 mips mipsel)
 set(MIPS64 mips64 mips64el)
 set(PPC32 powerpc)
 set(PPC64 powerpc64 powerpc64le)
 set(RISCV32 riscv32)

compiler-rt/lib/builtins/CMakeLists.txt

 set(arm64_SOURCES ${aarch64_SOURCES})
 set(arm64e_SOURCES ${aarch64_SOURCES})
 set(arm64_32_SOURCES ${aarch64_SOURCES})
 
 # macho_embedded archs
 set(armv6m_SOURCES ${thumb1_SOURCES})
 set(armv7m_SOURCES ${arm_SOURCES})
 set(armv7em_SOURCES ${arm_SOURCES})
+set(armv8m.main_SOURCES ${arm_SOURCES})
+set(armv8.1m.main_SOURCES ${arm_SOURCES})
 
 # hexagon arch
 set(hexagon_SOURCES
   hexagon/common_entry_exit_abi1.S
   hexagon/common_entry_exit_abi2.S
   hexagon/common_entry_exit_legacy.S
   hexagon/dfaddsub.S
   hexagon/dfdiv.S
if(COMPILER_RT_BUILTINS_HIDE_SYMBOLS)
     append_list_if(COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG VISIBILITY_HIDDEN BUILTIN_DEFS)
   endif()
 
   append_list_if(COMPILER_RT_HAS_ASM_LSE HAS_ASM_LSE BUILTIN_DEFS)
 
   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
     if (CAN_TARGET_${arch})
       # For ARM archs, exclude any VFP builtins if VFP is not supported
-      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
+      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em|armv8m.main|armv8.1m.main)$")
         string(REPLACE ";" " " _TARGET_${arch}_CFLAGS "${TARGET_${arch}_CFLAGS}")
         check_compile_definition(__ARM_FP "${CMAKE_C_FLAGS} ${_TARGET_${arch}_CFLAGS}" COMPILER_RT_HAS_${arch}_VFP)
         if(NOT COMPILER_RT_HAS_${arch}_VFP)
           list(REMOVE_ITEM ${arch}_SOURCES ${arm_Thumb1_VFPv2_DP_SOURCES} ${arm_Thumb1_VFPv2_SP_SOURCES} ${arm_Thumb1_SjLj_EH_SOURCES})
         else()
           # Exclude any double-precision builtins if VFP is single-precision-only
           try_compile_only(COMPILER_RT_HAS_${arch}_VFP_DP
                            SOURCE "#if !(__ARM_FP & 0x8)