Using MEM_SIZE is more general, since it copes with cases where targets are forced to use BLKmode references for whatever reason.
Thanks, Richard [ This patch is part of the SVE series posted here: https://gcc.gnu.org/ml/gcc/2016-11/msg00030.html ] gcc/ 2016-11-15 Richard Sandiford <richard.sandif...@arm.com> Alan Hayward <alan.hayw...@arm.com> David Sherwood <david.sherw...@arm.com> * dce.c (check_argument_store): Pass the size instead of the memory reference. (find_call_stack_args): Pass MEM_SIZE to check_argument_store. diff --git a/gcc/dce.c b/gcc/dce.c index 154469c..16340b64 100644 --- a/gcc/dce.c +++ b/gcc/dce.c @@ -234,16 +234,17 @@ mark_nonreg_stores (rtx body, rtx_insn *insn, bool fast) } -/* Return true if store to MEM, starting OFF bytes from stack pointer, +/* Return true if a store to SIZE bytes, starting OFF bytes from stack pointer, is a call argument store, and clear corresponding bits from SP_BYTES bitmap if it is. */ static bool -check_argument_store (rtx mem, HOST_WIDE_INT off, HOST_WIDE_INT min_sp_off, - HOST_WIDE_INT max_sp_off, bitmap sp_bytes) +check_argument_store (HOST_WIDE_INT size, HOST_WIDE_INT off, + HOST_WIDE_INT min_sp_off, HOST_WIDE_INT max_sp_off, + bitmap sp_bytes) { HOST_WIDE_INT byte; - for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++) + for (byte = off; byte < off + size; byte++) { if (byte < min_sp_off || byte >= max_sp_off @@ -468,8 +469,8 @@ find_call_stack_args (rtx_call_insn *call_insn, bool do_mark, bool fast, break; } - if (GET_MODE_SIZE (GET_MODE (mem)) == 0 - || !check_argument_store (mem, off, min_sp_off, + if (!MEM_SIZE_KNOWN_P (mem) + || !check_argument_store (MEM_SIZE (mem), off, min_sp_off, max_sp_off, sp_bytes)) break;
