On 27/02/14 22:32, Marcus Shawcroft wrote:
> On 21 February 2014 04:24, Kugan <kugan.vivekanandara...@linaro.org> wrote:
> 
>> Compiling inline asm results in ICE (PR60034). Alignment calculation in
>> aarch64_classify_address for (symbol_ref:DI ("*.LANCHOR4") [flags
>> 0x182])) seems wrong here.
> 
> Hi Kugan,
> 
> +      else if (SYMBOL_REF_FLAGS (sym))
> + align = GET_MODE_ALIGNMENT (GET_MODE (sym));
> 
> This is inserted into the LO_SUM handling in the function
> aarch64_classify_address(), the code in question is checking the
> alignment of the object to ensure that a scaled address instruction
> would be valid. The proposed code is testing if any of a bunch of
> unrelated predicate flags have been set on the symbol and using that
> to gate whether GET_MODE_ALIGNMENT would give accurate alignment
> information on the symbol. I'm not convinced that the presence of
> SYMBOL_REF_FLAGS states anything definitive about the relevance of
> GET_MODE_ALIGNMENT.   The test looks like it fails because a section
> anchor has been introduced and we fail to determine anything sensible
> about the alignment of a section anchor.  How about this instead?
> 
>  if (SYMBOL_REF_BLOCK (sym))
>    align = SYMBOL_REF_BLOCK (sym)->alignment;
> 

Thanks Marcus for the explanation.  I have now changed it based on this
and regression tested on qemu-aarch64 for aarch64-none-linux-gnu with no
new regressions.

Is this OK?

>>
>> Fixing this also  caused a regression for pr38151.c, which is due to
>> complex type being allocated with wrong alignment. Attached patch fixes
>> these issues.
> 
> It ~might~ be beneficial to increase data_alignment here as suggest
> for performance reasons, but the existing alignment should not cause
> breakage... this issue suggest to me that the SYMBOL_REF_FLAGS
> approach is at fault.
> 

Removing this hunk. I will post it as a desperate patch after more analysis.

Thanks,
Kugan


gcc/

2014-03-03  Kugan Vivekanandarajah  <kug...@linaro.org>

        PR target/60034
        * aarch64/aarch64.c (aarch64_classify_address): Fix alignment for
        section anchor.



gcc/testsuite/

2014-03-03  Kugan Vivekanandarajah  <kug...@linaro.org>

        PR target/60034
        * gcc.target/aarch64/pr60034.c: New file.

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 901ad3d..d2a9217 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -3199,6 +3199,10 @@ aarch64_classify_address (struct aarch64_address_info 
*info,
                }
              else if (SYMBOL_REF_DECL (sym))
                align = DECL_ALIGN (SYMBOL_REF_DECL (sym));
+             else if (SYMBOL_REF_HAS_BLOCK_INFO_P (sym)
+                      && SYMBOL_REF_ANCHOR_P (sym)
+                      && SYMBOL_REF_BLOCK (sym) != NULL)
+               align = SYMBOL_REF_BLOCK (sym)->alignment;
              else
                align = BITS_PER_UNIT;
 
diff --git a/gcc/testsuite/gcc.target/aarch64/pr60034.c 
b/gcc/testsuite/gcc.target/aarch64/pr60034.c
index e69de29..d126779 100644
--- a/gcc/testsuite/gcc.target/aarch64/pr60034.c
+++ b/gcc/testsuite/gcc.target/aarch64/pr60034.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -fgnu89-inline -O -Wall -Winline -Wwrite-strings 
-fmerge-all-constants -frounding-math -g -Wstrict-prototypes" } */
+
+static unsigned long global_max_fast;
+
+void __libc_mallopt (int param_number, int value)
+{
+ __asm__ __volatile__ ("# %[_SDT_A21]" :: [_SDT_A21] "nr" ((global_max_fast)));
+ global_max_fast = 1;
+}

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