* config/i386/i386.c (expand_setmem_via_rep_stos): Add ORIG_VALUE
argument. If ORIG_VALUE is const0_rtx and COUNT is constant,
set MEM_SIZE on DESTMEM.
(ix86_expand_setmem): Adjust callers.
PR target/38488
* expr.h (get_mem_align_offset): New prototype.
* emit-rtl.c (get_mem_align_offset): New function.
* config/i386/i386.c (expand_movmem_via_rep_mov): Set MEM_SIZE correctly.
(expand_constant_movmem_prologue, expand_constant_setmem_prologue):
New functions.
(ix86_expand_movmem): Optimize if COUNT_EXP
is constant, desired_align > align and dst & (desired_align - 1)
is computable at compile time.
(ix86_expand_setmem): Likewise.
* builtins.c (get_memory_rtx): Try to derive MEM_ATTRS from not yet
resolved SAVE_EXPR or POINTER_PLUS_EXPR.
From-SVN: r142891
