[Bug rtl-optimization/67753] [6 Regression] FAIL: cxg1005, cxg2002, cxg2006, cxg2007, cxg2008, cxg2018, cxg2019 and cxg2020

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67753

--- Comment #8 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
Author: aoliva
Date: Thu Nov 26 21:57:40 2015
New Revision: 230985

URL: https://gcc.gnu.org/viewcvs?rev=230985&root=gcc&view=rev
Log:
[PR67753] adjust for padding when bypassing memory in assign_parm_setup_block

Storing a register in memory as a full word and then accessing the
same memory address under a smaller-than-word mode amounts to
right-shifting of the register word on big endian machines.  So, if
BLOCK_REG_PADDING chooses upward padding for BYTES_BIG_ENDIAN, and
we're copying from the entry_parm REG directly to a pseudo, bypassing
any stack slot, perform the shifting explicitly.

This fixes the miscompile of function_return_val_10 in
gcc.target/aarch64/aapcs64/func-ret-4.c for target aarch64_be-elf
introduced in the first patch for 67753.

for  gcc/ChangeLog

        PR rtl-optimization/67753
        PR rtl-optimization/64164
        * function.c (assign_parm_setup_block): Right-shift
        upward-padded big-endian args when bypassing the stack slot.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/function.c