Hi, On Fri, Apr 06, 2012 at 06:13:20PM +0200, Eric Botcazou wrote: > > 2012-04-03 Martin Jambor <mjam...@suse.cz> > > > > * expr.c (expand_expr_real_1): Pass type, not the expression, to > > set_mem_attributes for a memory temporary. Do not call the > > function for temporaries with a different alias set. > > The last sentence is unprecise, this would rather be: "Do not call > the function for the memory temporary created for a bitfield".
OK > > I wonder whether we should simplify the bitfield case in the process. Once > we > remove the call to set_mem_attributes, I think the > > /* If the reference doesn't use the alias set of its type, > we cannot create the temporary using that type. */ > > is useless, so we could try to revert r122014 in the process. Well, the commit did not add a testcase and when I looked up the patch in the mailing list archive (http://gcc.gnu.org/ml/gcc-patches/2006-11/msg01449.html) it said it was fixing problems not reproducible on trunk so it's basically impossible for me to evaluate whether it is still necessary by some simple testing. Having said that, I guess I can give it a round of regular testing on all the platforms I have currently set up. On Fri, Apr 06, 2012 at 06:21:55PM +0200, Eric Botcazou wrote: > > @@ -9870,7 +9871,14 @@ expand_expr_real_1 (tree exp, rtx target > > if (op0 == orig_op0) > > op0 = copy_rtx (op0); > > > > - set_mem_attributes (op0, exp, 0); > > + /* If op0 is a temporary because of forcing to memory, pass only the > > + type to set_mem_attributes so that the original expression is never > > + marked as ADDRESSABLE through MEM_EXPR of the temporary. */ > > + if (mem_attrs_from_type) > > + set_mem_attributes (op0, TREE_TYPE (exp), 0); > > set_mem_attributes (op0, type, 0); is equivalent. > OK. So basically I'd like to commit the following. It has been successfully bootstrapped and tested on x86_64-linux, i686-linux, sparc64-linux (without Java), ia64-linux (without Ada) and tested on hppa-linux (C and C++ only). OK for trunk? Thanks, Martin 2012-04-10 Martin Jambor <mjam...@suse.cz> * expr.c (expand_expr_real_1): Pass type, not the expression, to set_mem_attributes for a memory temporary. Do not call the function for the memory temporary created for a bitfield. Index: src/gcc/expr.c =================================================================== --- src.orig/gcc/expr.c +++ src/gcc/expr.c @@ -9598,6 +9598,7 @@ expand_expr_real_1 (tree exp, rtx target tree tem = get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode1, &unsignedp, &volatilep, true); rtx orig_op0, memloc; + bool mem_attrs_from_type = false; /* If we got back the original object, something is wrong. Perhaps we are evaluating an expression too early. In any event, don't @@ -9703,6 +9704,7 @@ expand_expr_real_1 (tree exp, rtx target memloc = assign_temp (nt, 1, 1, 1); emit_move_insn (memloc, op0); op0 = memloc; + mem_attrs_from_type = true; } if (offset) @@ -9875,7 +9877,6 @@ expand_expr_real_1 (tree exp, rtx target emit_move_insn (new_rtx, op0); op0 = copy_rtx (new_rtx); PUT_MODE (op0, BLKmode); - set_mem_attributes (op0, exp, 1); } return op0; @@ -9896,7 +9897,14 @@ expand_expr_real_1 (tree exp, rtx target if (op0 == orig_op0) op0 = copy_rtx (op0); - set_mem_attributes (op0, exp, 0); + /* If op0 is a temporary because of forcing to memory, pass only the + type to set_mem_attributes so that the original expression is never + marked as ADDRESSABLE through MEM_EXPR of the temporary. */ + if (mem_attrs_from_type) + set_mem_attributes (op0, type, 0); + else + set_mem_attributes (op0, exp, 0); + if (REG_P (XEXP (op0, 0))) mark_reg_pointer (XEXP (op0, 0), MEM_ALIGN (op0));
