[PATCH][ARM] Use __ARM_ARCH instead of __ARM_ARCH__

[Kyrill Tkachov]

Hi Christophe,

On 17/06/18 21:23, Christophe Lyon wrote:
> On Fri, 15 Jun 2018 at 17:22, Richard Earnshaw (lists)
> <Richard.Earnshaw@arm.com> wrote:
> >
> > On 15/06/18 15:30, Christophe Lyon wrote:
> > > Hello,
> > >
> > > As suggested in [1], the attached patch removes all definitions and
> > > uses of __ARM_ARCH__ and uses __ARM_ARCH instead. The later is indeed
> > > defined by the preprocessor to the appropriate value.
> > >
> > > I ran make check on arm-none-eabi (with A-profile multilib),
> > > arm-none-linux-gnueabi, arm-none-linux-gnueabihf (with cortex-a9, a15,
> > > a5, a57 and armtdmi as --with-cpu), armeb-none-linux-gnueabihf and
> > > armv8l-linux-gnueabihf, and noticed no regression.
> > >
> > > OK for trunk?
> > >
> > > Thanks,
> > >
> > > Christophe
> > >
> > > [1] https://gcc.gnu.org/ml/gcc-patches/2018-06/msg00445.html
> > >
> > >
> > > ARM_ARCH.chlog.txt
> > >
> > >
> > > libatomic/ChangeLog:
> > >
> > > 2018-06-15  Christophe Lyon <christophe.lyon@linaro.org>
> > >
> > >       * config/arm/arm-config.h (__ARM_ARCH__): Remove definitions, use
> > >       __ARM_ARCH instead.
> > >
> > > libgcc/ChangeLog:
> > >
> > > 2018-06-15  Christophe Lyon <christophe.lyon@linaro.org>
> > >
> > >       * config/arm/lib1funcs.S (__ARM_ARCH__): Remove definitions, use
> > >       __ARM_ARCH instead.
> > >       * config/arm/ieee754-df.S: Use __ARM_ARCH instead of __ARM_ARCH__.
> > >       * config/arm/ieee754-sf.S: Likewise.
> > >       * config/arm/libunwind.S: Likewise.
> > >
> > >
> > > ARM_ARCH.patch.txt
> > >
> >
> > Thanks, this is a useful start.  We can, however, go further.  ACLE
> > defines a number of 'feature' pre-defines and we can use those to void
> > direct tests of the architecture version directly.  For example,
> > __ARM_FEATURE_LDREX could directly replace having to calculate
> > HAVE_STREX and HAVE_STREXBHD.
> >
> Hi,
>
> Here is an updated patch using __ARM_FEATURE_LDREX.
> I didn't find other opportunities to use ACLE pre-defines, did I miss any?
>

Thanks for doing this. I think we can catch a few more...

diff --git a/libgcc/config/arm/ieee754-df.S b/libgcc/config/arm/ieee754-df.S
index 570e5f6..7c5260e 100644
--- a/libgcc/config/arm/ieee754-df.S
+++ b/libgcc/config/arm/ieee754-df.S
@@ -245,7 +245,7 @@ LSYM(Lad_a):
  	@ No rounding necessary since ip will always be 0 at this point.
  LSYM(Lad_l):
  
-#if __ARM_ARCH__ < 5
+#if __ARM_ARCH < 5
  
This path exists to handle the case when the CLZ instruction is not available (the #else path uses CLZ).
So we can change this to #ifndef __ARM_FEATURE_CLZ


  	teq	xh, #0
  	movne	r3, #20
@@ -656,7 +656,7 @@ ARM_FUNC_ALIAS aeabi_dmul muldf3
  	orr	yh, yh, #0x00100000
  	beq	LSYM(Lml_1)
  
-#if __ARM_ARCH__ < 4
+#if __ARM_ARCH < 4
  
We can delete this whole path as we no longer support anything older than 4

diff --git a/libgcc/config/arm/ieee754-sf.S b/libgcc/config/arm/ieee754-sf.S
index dac3e2e..00a8d9c 100644
--- a/libgcc/config/arm/ieee754-sf.S
+++ b/libgcc/config/arm/ieee754-sf.S
@@ -175,7 +175,7 @@ LSYM(Lad_a):
  	@ No rounding necessary since r1 will always be 0 at this point.
  LSYM(Lad_l):
  
-#if __ARM_ARCH__ < 5
+#if __ARM_ARCH < 5
  
  	movs	ip, r0, lsr #12
  	moveq	r0, r0, lsl #12
@@ -370,7 +370,7 @@ ARM_FUNC_ALIAS aeabi_l2f floatdisf
  	subeq	r3, r3, #(32 << 23)
  2:	sub	r3, r3, #(1 << 23)
  
-#if __ARM_ARCH__ < 5
+#if __ARM_ARCH < 5
  
  	mov	r2, #23
  	cmp	ip, #(1 << 16)

Similar comment on checking __ARM_FEATURE_CLZ in the above two checks.


  @@ -460,7 +460,7 @@ LSYM(Lml_x):
  	orr	r0, r3, r0, lsr #5
  	orr	r1, r3, r1, lsr #5
  
-#if __ARM_ARCH__ < 4
+#if __ARM_ARCH < 4
  
  	@ Put sign bit in r3, which will be restored into r0 later.
  	and	r3, ip, #0x80000000


Likewise on deleting the < 4 path.

diff --git a/libgcc/config/arm/lib1funcs.S b/libgcc/config/arm/lib1funcs.S
index 04c1b77..264d54a 100644
--- a/libgcc/config/arm/lib1funcs.S
+++ b/libgcc/config/arm/lib1funcs.S
@@ -74,49 +74,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  
<snip>
  
-#if __ARM_ARCH__ >= 5 && ! defined (__OPTIMIZE_SIZE__)
+#if __ARM_ARCH >= 5 && ! defined (__OPTIMIZE_SIZE__)


Likewise I believe this check should be for __ARM_FEATURE_CLZ, with the rest of the #elses
updated accordingly.

<snip>

@@ -1701,8 +1658,8 @@ LSYM(Lover12):
  
  #if (__ARM_ARCH_ISA_THUMB == 2	\
       || (__ARM_ARCH_ISA_ARM	\
-	 && (__ARM_ARCH__ > 5	\
-	     || (__ARM_ARCH__ == 5 && __ARM_ARCH_ISA_THUMB))))
+	 && (__ARM_ARCH > 5	\
+	     || (__ARM_ARCH == 5 && __ARM_ARCH_ISA_THUMB))))
  #define HAVE_ARM_CLZ 1
  #endif

This HAVE_ARM_CLZ should now be redundant as we can update its uses to __ARM_FEATURE_CLZ

Thanks,
Kyrill