Re: [PATCH v4 4/6] ArmPkg/Library/CompilerIntrinsicsLib: Enable VS2017/ARM builds

[Pete Batard <pete@akeo.ie>]

Eugene,

How about I modify the patch to use "AREA s_<original_func_name>" 
instead of "AREA Math" as per the current proposal?

I believe this should achieve the same result as the one you want, 
without having to rely on introducing conditional differences between 
MSFT and RVCT, which are going to make the code harder to maintain.

In the places we modified, there was exactly 1 use of the macro per 
file, which means that, we should be able to "unroll" the macro and 
preserve the existing behaviour, while keeping MSFT happy without having 
to define separate macros and conditional stuff.

Also, you'll notice that the current div.asm [1], which is used by RVCT 
does *not* rely on the macro, so, unless this is intentional, there 
already seems to exist inconsistencies with regards to using the 
RVCT_ASM_EXPORT macro to ensure the removal of dead code...

So, to summarise, I would much prefer if we could keep most of the 
current patch, and simply use the following where needed:

AREA  s___aeabi_ldivmod, CODE, READONLY, ARM
AREA  s___aeabi_llsr, CODE, READONLY, ARM
AREA  s___aeabi_uldivmod, CODE, READONLY, ARM

What do you think?

Regards,

/Pete

[1] 
https://github.com/tianocore/edk2/blob/master/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm

On 2018.01.11 15:30, Cohen, Eugene wrote:
> 
>>> Introduce CRT assembly replacements for __rt_sdiv, __rt_udiv,
>>> __rt_udiv64, __rt_sdiv64, __rt_srsh (by reusing the RVCT code) as well
>>> as memcpy and memset.
>>> For MSFT compatibility, some of the code needs to be explicitly forced
>>> to ARM, and the /oldit assembly flag needs to be added.
>>>
>>> Contributed-under: TianoCore Contribution Agreement 1.1
>>> Signed-off-by: Pete Batard <pete@akeo.ie>
>>
>> This looks fine to me but I haven't been able to test it.
>>
>> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>
>> Eugene: any comments regarding the changes to RVCT code?
> 
> I've been away in Linux land for a while, it's nice that the day I catch up on my edk2-devel backlog I see my name! :)
> 
> One concern for RVCT is that every function is in its own section to enable proper dead code removal.  This is addressed with this macro:
> 
>    MACRO
>    RVCT_ASM_EXPORT $func
>      EXPORT  $func
>      AREA s_$func, CODE, READONLY
> $func
>    MEND
> 
> note the AREA directive - this makes a section per function.
> 
> Pete's patchset removes these macros which breaks dead code removal.
> 
> Please restore these macros for at least RVCT and please verify that the VS2017 path does appropriate dead code removal for these assembly functions.
> 
> Thanks!
> 
> Eugene
> 
>>
>>
>>> ---
>>>   ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm               | 43
>> +++++++++++++++++---
>>>   ArmPkg/Library/CompilerIntrinsicsLib/Arm/ldivmod.asm           | 40
>> +++++++++++++-----
>>>   ArmPkg/Library/CompilerIntrinsicsLib/Arm/llsr.asm              | 22 +++++----
>> -
>>>   ArmPkg/Library/CompilerIntrinsicsLib/Arm/uldiv.asm             | 29
>> +++++++++++--
>>>   ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf | 16
>> +++++++-
>>>   ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c               | 34
>> ++++++++++++++++
>>>   ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c               | 33
>> +++++++++++++++
>>>   7 files changed, 185 insertions(+), 32 deletions(-)
>>>
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm
>>> index b539e516892d..f9e0107395f2 100644
>>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm
>>> @@ -1,6 +1,7 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>   //
>>>   // Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
>>> +// Copyright (c) 2018, Pete Batard. All rights reserved.<BR>
>>>   //
>>>   // This program and the accompanying materials  // are licensed and
>>> made available under the terms and conditions of the BSD License @@
>>> -17,18 +18,19 @@
>>>       EXPORT  __aeabi_uidivmod
>>>       EXPORT  __aeabi_idiv
>>>       EXPORT  __aeabi_idivmod
>>> +    EXPORT  __rt_udiv
>>> +    EXPORT  __rt_sdiv
>>>
>>>       AREA  Math, CODE, READONLY
>>>
>>>   ;
>>>   ;UINT32
>>>   ;EFIAPI
>>> -;__aeabi_uidivmode (
>>> -;  IN UINT32  Dividen
>>> +;__aeabi_uidivmod (
>>> +;  IN UINT32  Dividend
>>>   ;  IN UINT32  Divisor
>>>   ;  );
>>>   ;
>>> -
>>>   __aeabi_uidiv
>>>   __aeabi_uidivmod
>>>       RSBS    r12, r1, r0, LSR #4
>>> @@ -40,10 +42,40 @@ __aeabi_uidivmod
>>>       B       __arm_div_large
>>>
>>>   ;
>>> +;UINT64
>>> +;EFIAPI
>>> +;__rt_udiv (
>>> +;  IN UINT32  Divisor,
>>> +;  IN UINT32  Dividend
>>> +;  );
>>> +;
>>> +__rt_udiv
>>> +    ; Swap R0 and R1
>>> +    MOV     r12, r0
>>> +    MOV     r0, r1
>>> +    MOV     r1, r12
>>> +    B       __aeabi_uidivmod
>>> +
>>> +;
>>> +;UINT64
>>> +;EFIAPI
>>> +;__rt_sdiv (
>>> +;  IN INT32  Divisor,
>>> +;  IN INT32  Dividend
>>> +;  );
>>> +;
>>> +__rt_sdiv
>>> +    ; Swap R0 and R1
>>> +    MOV     r12, r0
>>> +    MOV     r0, r1
>>> +    MOV     r1, r12
>>> +    B       __aeabi_idivmod
>>> +
>>> +;
>>>   ;INT32
>>>   ;EFIAPI
>>> -;__aeabi_idivmode (
>>> -;  IN INT32  Dividen
>>> +;__aeabi_idivmod (
>>> +;  IN INT32  Dividend
>>>   ;  IN INT32  Divisor
>>>   ;  );
>>>   ;
>>> @@ -152,4 +184,3 @@ __aeabi_idiv0
>>>       BX      r14
>>>
>>>       END
>>> -
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/ldivmod.asm
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/ldivmod.asm
>>> index c71bd59e4520..3794cac35eed 100644
>>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/ldivmod.asm
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/ldivmod.asm
>>> @@ -1,6 +1,7 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>   //
>>>   // Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
>>> +// Copyright (c) 2018, Pete Batard. All rights reserved.<BR>
>>>   //
>>>   // This program and the accompanying materials  // are licensed and
>>> made available under the terms and conditions of the BSD License @@
>>> -13,20 +14,41 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>
>>>
>>> -    EXTERN  __aeabi_uldivmod
>>> +    IMPORT  __aeabi_uldivmod
>>> +    EXPORT  __aeabi_ldivmod
>>> +    EXPORT  __rt_sdiv64
>>>
>>> -    INCLUDE AsmMacroExport.inc
>>> +    AREA  Math, CODE, READONLY, ARM
>>> +
>>> +    ARM
>>>
>>>   ;
>>> -;UINT32
>>> +;INT64
>>>   ;EFIAPI
>>> -;__aeabi_uidivmode (
>>> -;  IN UINT32  Dividen
>>> -;  IN UINT32  Divisor
>>> +;__rt_sdiv64 (
>>> +;  IN  INT64  Divisor
>>> +;  IN  INT64  Dividend
>>>   ;  );
>>>   ;
>>> +__rt_sdiv64
>>> +    ; Swap r0-r1 and r2-r3
>>> +    MOV     r12, r0
>>> +    MOV     r0, r2
>>> +    MOV     r2, r12
>>> +    MOV     r12, r1
>>> +    MOV     r1, r3
>>> +    MOV     r3, r12
>>> +    B       __aeabi_ldivmod
>>>
>>> - RVCT_ASM_EXPORT __aeabi_ldivmod
>>> +;
>>> +;INT64
>>> +;EFIAPI
>>> +;__aeabi_ldivmod (
>>> +;  IN  INT64  Dividend
>>> +;  IN  INT64  Divisor
>>> +;  );
>>> +;
>>> +__aeabi_ldivmod
>>>       PUSH     {r4,lr}
>>>       ASRS     r4,r1,#1
>>>       EOR      r4,r4,r3,LSR #1
>>> @@ -39,7 +61,7 @@ L_Test1
>>>       RSBS     r2,r2,#0
>>>       RSC      r3,r3,#0
>>>   L_Test2
>>> -    BL       __aeabi_uldivmod  ;
>>> +    BL       __aeabi_uldivmod
>>>       TST      r4,#0x40000000
>>>       BEQ      L_Test3
>>>       RSBS     r0,r0,#0
>>> @@ -53,5 +75,3 @@ L_Exit
>>>       POP      {r4,pc}
>>>
>>>       END
>>> -
>>> -
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/llsr.asm
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/llsr.asm
>>> index 881db106d9d7..db2fd5057832 100644
>>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/llsr.asm
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/llsr.asm
>>> @@ -1,6 +1,7 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>   //
>>>   // Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
>>> +// Copyright (c) 2018, Pete Batard. All rights reserved.<BR>
>>>   //
>>>   // This program and the accompanying materials  // are licensed and
>>> made available under the terms and conditions of the BSD License @@
>>> -12,32 +13,33 @@  //
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>
>>> +  EXPORT  __aeabi_llsr
>>> +  EXPORT  __rt_srsh
>>>
>>> +  AREA  Math, CODE, READONLY, ARM
>>>
>>> -    INCLUDE AsmMacroExport.inc
>>> +  ARM
>>>
>>>   ;
>>>   ;VOID
>>>   ;EFIAPI
>>>   ;__aeabi_llsr (
>>> -; IN  VOID    *Destination,
>>> -; IN  VOID    *Source,
>>> -; IN  UINT32  Size
>>> -; );
>>> +;  IN  UINT64  Value,
>>> +;  IN  UINT32  Shift
>>> +;)
>>>   ;
>>> - RVCT_ASM_EXPORT __aeabi_llsr
>>> +__aeabi_llsr
>>> +__rt_srsh
>>>       SUBS     r3,r2,#0x20
>>> -    BPL      {pc} + 0x18  ; 0x1c
>>> +    BPL      __aeabi_llsr_label1
>>>       RSB      r3,r2,#0x20
>>>       LSR      r0,r0,r2
>>>       ORR      r0,r0,r1,LSL r3
>>>       LSR      r1,r1,r2
>>>       BX       lr
>>> +__aeabi_llsr_label1
>>>       LSR      r0,r1,r3
>>>       MOV      r1,#0
>>>       BX       lr
>>>
>>>       END
>>> -
>>> -
>>> -
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uldiv.asm
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uldiv.asm
>>> index 6b6184ebd3fc..c5632b4e95e7 100644
>>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uldiv.asm
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uldiv.asm
>>> @@ -1,6 +1,7 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>   //
>>>   // Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
>>> +// Copyright (c) 2018, Pete Batard. All rights reserved.<BR>
>>>   //
>>>   // This program and the accompanying materials  // are licensed and
>>> made available under the terms and conditions of the BSD License @@
>>> -13,9 +14,30 @@
>>>
>>> //--------------------------------------------------------------------
>>> ----------
>>>
>>>
>>> +    EXPORT  __aeabi_uldivmod
>>> +    EXPORT  __rt_udiv64
>>>
>>> +    AREA  Math, CODE, READONLY, ARM
>>>
>>> -    INCLUDE AsmMacroExport.inc
>>> +    ARM
>>> +
>>> +;
>>> +;UINT64
>>> +;EFIAPI
>>> +;__rt_udiv64 (
>>> +;  IN  UINT64   Divisor
>>> +;  IN  UINT64   Dividend
>>> +;  )
>>> +;
>>> +__rt_udiv64
>>> +  ; Swap r0-r1 and r2-r3
>>> +  mov     r12, r0
>>> +  mov     r0, r2
>>> +  mov     r2, r12
>>> +  mov     r12, r1
>>> +  mov     r1, r3
>>> +  mov     r3, r12
>>> +  b       __aeabi_uldivmod
>>>
>>>   ;
>>>   ;UINT64
>>> @@ -25,7 +47,7 @@
>>>   ;  IN  UINT64   Divisor
>>>   ;  )
>>>   ;
>>> - RVCT_ASM_EXPORT __aeabi_uldivmod
>>> +__aeabi_uldivmod
>>>     stmdb   sp!, {r4, r5, r6, lr}
>>>     mov     r4, r1
>>>     mov     r5, r0
>>> @@ -261,7 +283,6 @@ _ll_div0
>>>     b       __aeabi_ldiv0
>>>
>>>   __aeabi_ldiv0
>>> -  BX        r14
>>> +  bx        r14
>>>
>>>     END
>>> -
>>> diff --git
>>> a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
>>> index 44333141a70a..14e88da7ce06 100644
>>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
>>> @@ -23,8 +23,12 @@ [Defines]
>>>     LIBRARY_CLASS                  = CompilerIntrinsicsLib
>>>
>>>   [Sources]
>>> -  memcpy.c
>>> -  memset.c
>>> +  memcpy.c             | RVCT
>>> +  memcpy.c             | GCC
>>> +  memcpy_ms.c          | MSFT
>>> +  memset.c             | RVCT
>>> +  memset.c             | GCC
>>> +  memset_ms.c          | MSFT
>>>
>>>   [Sources.ARM]
>>>     Arm/mullu.asm        | RVCT
>>> @@ -94,6 +98,10 @@ [Sources.ARM]
>>>     Arm/llsr.S       | GCC
>>>     Arm/llsl.S       | GCC
>>>
>>> +  Arm/div.asm      | MSFT
>>> +  Arm/uldiv.asm    | MSFT
>>> +  Arm/ldivmod.asm  | MSFT
>>> +  Arm/llsr.asm     | MSFT
>>>
>>>   [Packages]
>>>     MdePkg/MdePkg.dec
>>> @@ -101,3 +109,7 @@ [Packages]
>>>
>>>   [LibraryClasses]
>>>
>>> +[BuildOptions]
>>> +  MSFT:*_*_ARM_CC_FLAGS = /GL-
>>> +  MSFT:*_*_ARM_ASM_FLAGS = /oldit
>>> +  MSFT:*_*_AARCH64_CC_FLAGS = /GL-
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c
>>> new file mode 100644
>>> index 000000000000..90bbbb930d31
>>> --- /dev/null
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c
>>> @@ -0,0 +1,34 @@
>>> +//-------------------------------------------------------------------
>>> +-----------
>>> +//
>>> +// Copyright (c) 2017, Pete Batard. All rights reserved.<BR> // //
>>> +This program and the accompanying materials are licensed and made //
>>> +available under the terms and conditions of the BSD License which //
>>> +accompanies this distribution.  The full text of the license may be
>>> +// found at http://opensource.org/licenses/bsd-license.php
>>> +//
>>> +// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS
>> IS"
>>> +BASIS, // WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND,
>> EITHER
>>> +EXPRESS OR // IMPLIED.
>>> +//
>>> +//-------------------------------------------------------------------
>>> +-----------
>>> +
>>> +#if defined(_M_ARM64)
>>> +typedef unsigned __int64  size_t;
>>> +#else
>>> +typedef unsigned __int32  size_t;
>>> +#endif
>>> +
>>> +void* memcpy(void *, const void *, size_t); #pragma intrinsic(memcpy)
>>> +#pragma function(memcpy)
>>> +void* memcpy(void *dest, const void *src, size_t n) {
>>> +  unsigned char *d = dest;
>>> +  unsigned char const *s = src;
>>> +
>>> +  while (n--)
>>> +    *d++ = *s++;
>>> +
>>> +  return dest;
>>> +}
>>> diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c
>>> b/ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c
>>> new file mode 100644
>>> index 000000000000..64205e5d1012
>>> --- /dev/null
>>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c
>>> @@ -0,0 +1,33 @@
>>> +//-------------------------------------------------------------------
>>> +-----------
>>> +//
>>> +// Copyright (c) 2017, Pete Batard. All rights reserved.<BR> // //
>>> +This program and the accompanying materials are licensed and made //
>>> +available under the terms and conditions of the BSD License which //
>>> +accompanies this distribution.  The full text of the license may be
>>> +// found at http://opensource.org/licenses/bsd-license.php
>>> +//
>>> +// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS
>> IS"
>>> +BASIS, // WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND,
>> EITHER
>>> +EXPRESS OR // IMPLIED.
>>> +//
>>> +//-------------------------------------------------------------------
>>> +-----------
>>> +
>>> +#if defined(_M_ARM64)
>>> +typedef unsigned __int64  size_t;
>>> +#else
>>> +typedef unsigned __int32  size_t;
>>> +#endif
>>> +
>>> +void* memset(void *, int, size_t);
>>> +#pragma intrinsic(memset)
>>> +#pragma function(memset)
>>> +void *memset(void *s, int c, size_t n) {
>>> +  unsigned char *d = s;
>>> +
>>> +  while (n--)
>>> +    *d++ = (unsigned char)c;
>>> +
>>> +  return s;
>>> +}
>>> --
>>> 2.9.3.windows.2
>>>