Re: [RFC PATCH v5] MIPS: fix build with binutils 2.24.51+

[Markos Chandras <Markos.Chandras@imgtec.com>]

On 10/30/2014 08:24 PM, Manuel Lauss wrote:
> Starting with version 2.24.51.20140728 MIPS binutils complain loudly
> about mixing soft-float and hard-float object files, leading to this
> build failure since GCC is invoked with "-msoft-float" on MIPS:
> 
> {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat'
>   LD      arch/mips/alchemy/common/built-in.o
> mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o
>  uses -msoft-float (set by arch/mips/alchemy/common/prom.o),
>  arch/mips/alchemy/common/sleeper.o uses -mhard-float
> 
> To fix this, we detect if GAS is new enough to support "-msoft-float" command
> option, and if it does, we can let GCC pass it to GAS;  but then we also need
> to sprinkle the files which make use of floating point registers with the
> necessary ".set hardfloat" directives.
> 
> Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
> ---
> Compiles with binutils 2.23 and current git head, 32bit mips32r1 tested only.
> 
> Tests on 64bit and with MSA and other extensions also appreciated!
> Markos: I can't reproduce the malta defconfig error you're seeing, at least
> not with sourceware sources.
> 
> v5: fixed issues with code for 32bit mips32r2 using .set mips64r2 outlined
>     by Matthew: what the code really wants is 64bit float support, but not
>     64bit mips code.
> 
> v4: fixed issues outlined by Markos and Matthew.
> 
> v3: incorporate Maciej's suggestions:
> 	- detect if gas can handle -msoft-float and ".set hardfloat"
> 	- apply .set hardfloat only where really necessary
> 
> v2: cover more files
> 
> This was introduced in binutils commit  351cdf24d223290b15fa991e5052ec9e9bd1e284
> ("[MIPS] Implement O32 FPXX, FP64 and FP64A ABI extensions").
> 

Hello,

I still can't build it with the toolchain I am using over here. This is
with a regular maltasmvp_defconfig

arch/mips/kernel/r4k_fpu.S: Assembler messages:
arch/mips/kernel/r4k_fpu.S:47: Warning: tried to set unrecognized
symbol: $30=64

arch/mips/kernel/r4k_fpu.S:54: Error: float register should be even, was 1
arch/mips/kernel/r4k_fpu.S:55: Error: float register should be even, was 3
arch/mips/kernel/r4k_fpu.S:56: Error: float register should be even, was 5
arch/mips/kernel/r4k_fpu.S:57: Error: float register should be even, was 7
arch/mips/kernel/r4k_fpu.S:58: Error: float register should be even, was 9
arch/mips/kernel/r4k_fpu.S:59: Error: float register should be even, was 11
arch/mips/kernel/r4k_fpu.S:60: Error: float register should be even, was 13
arch/mips/kernel/r4k_fpu.S:61: Error: float register should be even, was 15
arch/mips/kernel/r4k_fpu.S:62: Error: float register should be even, was 17
arch/mips/kernel/r4k_fpu.S:63: Error: float register should be even, was 19
arch/mips/kernel/r4k_fpu.S:64: Error: float register should be even, was 21
arch/mips/kernel/r4k_fpu.S:65: Error: float register should be even, was 23
arch/mips/kernel/r4k_fpu.S:66: Error: float register should be even, was 25
arch/mips/kernel/r4k_fpu.S:67: Error: float register should be even, was 27
arch/mips/kernel/r4k_fpu.S:68: Error: float register should be even, was 29
arch/mips/kernel/r4k_fpu.S:69: Error: float register should be even, was 31
arch/mips/kernel/r4k_fpu.S:168: Warning: tried to set unrecognized
symbol: $30=64


-- 
markos