Thread overview
Compiler error when compiling druntime for ARM float=soft
Apr 15
IGotD-
Apr 15
kinke
Apr 15
IGotD-
April 15
I'm trying get druntime to compile for ARMv7 but with software floating point. When the first druntime module try to compile I get this error.

LVM ERROR: Cannot select: 0x8818a78: f64 = bitcast 0x88186d0
  0x88186d0: i64 = build_pair 0x8819090, 0x88191c8
    0x8819090: i32,ch = CopyFromReg 0x8575238, Register:i32 %15
      0x865fae0: i32 = Register %15
    0x88191c8: i32,ch = CopyFromReg 0x8819090:1, Register:i32 %16
      0x8818db8: i32 = Register %16
In function: _memset80

Among other things I'm using the following architecture flags when compiling, this for a custom target.

--dFlags=-mtriple=arm-none-eabi --dFlags=-mcpu=cortex-a9 --dFlags=--mattr=+thumb2 --dFlags=--mattr=+soft-float --dFlags=--relocation-model=pic

If I remove "--dFlags=--mattr=+soft-float", the build succeeds (only the first module, however that's the only one I'm interested in for now, ldc-build-runtime inserts double --dFlags=--relocation-model=pic which the build doesn't like when compiling the shared library version which is strange because I have added BUILD_SHARED_LIBS=OFF).
April 15
On Wednesday, 15 April 2020 at 18:31:55 UTC, IGotD- wrote:
> I'm trying get druntime to compile for ARMv7 but with software floating point. When the first druntime module try to compile I get this error.

It's easier if you just post a failing cmdline, which in this case is something like

ldc2 -c .../druntime/src/rt/memset.d -mtriple=armv7-none-eabi -mcpu=cortex-a9 -float-abi=soft -O

It's compiling fine without -O; with optimizations, LLVM (10) hits an assertion (if built with those enabled, otherwise errors out later as you've seen). So might be worth filing an LLVM issue about it. [It's also optimized fine with `-float-abi=softfp`.]

Luckily, this rt.memset module seems utterly useless for LDC, so you shouldn't need it and can simply delete the source file.

PS: I hope you are using COMPILE_ALL_D_FILES_AT_ONCE=OFF when working on the libraries.
April 15
On Wednesday, 15 April 2020 at 19:51:37 UTC, kinke wrote:
>
> It's easier if you just post a failing cmdline, which in this case is something like
>
> ldc2 -c .../druntime/src/rt/memset.d -mtriple=armv7-none-eabi -mcpu=cortex-a9 -float-abi=soft -O
>
> It's compiling fine without -O; with optimizations, LLVM (10) hits an assertion (if built with those enabled, otherwise errors out later as you've seen). So might be worth filing an LLVM issue about it. [It's also optimized fine with `-float-abi=softfp`.]
>
> Luckily, this rt.memset module seems utterly useless for LDC, so you shouldn't need it and can simply delete the source file.
>
> PS: I hope you are using COMPILE_ALL_D_FILES_AT_ONCE=OFF when working on the libraries.

I did what you suggested, I added COMPILE_ALL_D_FILES_AT_ONCE=OFF and removed memset.d from the build and now the first build goes through.

I thought memset.d was kind of strange as this was something that could obviously be mitigated to LLVM. Shouldn't this be removed from the build in the cmake file?

Thank you.