WIP: equivalent of LLVM's -arm-assume-misaligned-load-storelinaro-local/arm-assume-misaligned-load-store

I've received a support request where GCC generates strd/ldrd which
require aligned memory addresses, while the user code actually
provides sub-aligned pointers.

The sample code is derived from CMSIS:

void foo(short *pDst, int in1, int in2) {
   *__SIMD32(pDst)++ = in1;
      *__SIMD32(pDst)++ = in2;
      }

compiled with arm-none-eabi-gcc -mcpu=cortex-m7 CMSIS.c -S -O2
generates:
foo:
        strd    r1, r2, [r0]
	        bx      lr

Using -mno-unaligned-access of course makes no change, since the code
is lying to the compiler by casting short* to int*.

However, LLVM has -arm-assume-misaligned-load-store which disables
generation of ldrd/strd in such cases:
https://reviews.llvm.org/D17015?id=48020

Change-Id: I576cbe22d6a109da4bb3bc5bda255dad4cc75ff8

0 files changed, 0 insertions, 0 deletions