From 240f9c2b138280b1ed94ead778cf68c24a8a48d7 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 23 Jan 2001 18:23:54 -0800 Subject: [PATCH] flow.c (init_propagate_block_info): Don't consider unchanging memories for dead frame store elimination. * flow.c (init_propagate_block_info): Don't consider unchanging memories for dead frame store elimination. From-SVN: r39222 --- gcc/ChangeLog | 5 +++++ gcc/flow.c | 7 +++++++ 2 files changed, 12 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 602dd5fa7e4..a1ca492a17c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2001-01-23 Richard Henderson + + * flow.c (init_propagate_block_info): Don't consider unchanging + memories for dead frame store elimination. + 2001-01-23 Richard Henderson * varasm.c (UNIQUE_SECTION): Move default implementation ... diff --git a/gcc/flow.c b/gcc/flow.c index 2e76e3d398f..00529d9d5e8 100644 --- a/gcc/flow.c +++ b/gcc/flow.c @@ -4100,6 +4100,13 @@ init_propagate_block_info (bb, live, local_set, cond_local_set, flags) { rtx mem = SET_DEST (PATTERN (insn)); + /* This optimization is performed by faking a store to the + memory at the end of the block. This doesn't work for + unchanging memories because multiple stores to unchanging + memory is illegal and alias analysis doesn't consider it. */ + if (RTX_UNCHANGING_P (mem)) + continue; + if (XEXP (mem, 0) == frame_pointer_rtx || (GET_CODE (XEXP (mem, 0)) == PLUS && XEXP (XEXP (mem, 0), 0) == frame_pointer_rtx