On Tue, Jan 4, 2022 at 9:59 AM Gary Oblock <g...@amperecomputing.com> wrote: > > Richard, > > Well during my exploration of pretty printing I spent > a bunch of time looking at mem refs, hence the question. > > I understand GIMPLE is not an AST. I worked on a > in house compiler someplace where the only IR was > an AST and it was a really horrible IR so I'm glad GIMPLE > isn't an AST. But the tree expressions seem to be chunks > of AST (with some other stuff thrown in that could be thought of > as node attributes.) Am I wrong to think of them that way?
trees are dual-purpose. It simply shows that GCC evolved over its lifetime ;) Richard. > Thanks, > > Gary > > > ________________________________ > From: Richard Biener <richard.guent...@gmail.com> > Sent: Monday, January 3, 2022 11:28 PM > To: Gary Oblock <g...@amperecomputing.com> > Cc: gcc@gcc.gnu.org <gcc@gcc.gnu.org> > Subject: Re: Why do these two trees print differently > > [EXTERNAL EMAIL NOTICE: This email originated from an external sender. Please > be mindful of safe email handling and proprietary information protection > practices.] > > > On Mon, Jan 3, 2022 at 9:16 PM Gary Oblock <g...@amperecomputing.com> wrote: > > > > Richard, > > > > I was able figure it out by looking for "MEM" is > > tree-pretty-print.c. There is the condition included > > at the end of the email (mostly to provoke a chuckle) > > necessary for the "p->f" format. If it's not true then > > the MEM form is emitted. > > Yes, there's some loss of information so we don't > "pretty" print the MEM. > > > > > What is most interesting from this whole exercise > > the question of why am I seeing offsets in > > the GIMPLE form? I'm seeing offsets where > > the symbolic form using field seems to make > > more sense. I'm also seeing accesses with > > offsets that are multiples of the structure size. > > That kind of idiom seems more appropriate at the > > RTL level. > > That seems to be an unrelated question? Note that GIMPLE > is much closer to RTL than you think - GIMPLE is _not_ an AST. > You see offsets whenever symbolic (COMPONENT_REF I suppose) > is eventually not semantically correct. > > Richard. > > > > > Thanks, > > > > Gary > > > > TREE_CODE (node) == MEM_REF > > && integer_zerop (TREE_OPERAND (node, 1)) > > /* Dump the types of INTEGER_CSTs explicitly, for we can't > > infer them and MEM_ATTR caching will share MEM_REFs > > with differently-typed op0s. */ > > && TREE_CODE (TREE_OPERAND (node, 0)) != INTEGER_CST > > /* Released SSA_NAMES have no TREE_TYPE. */ > > && TREE_TYPE (TREE_OPERAND (node, 0)) != NULL_TREE > > /* Same pointer types, but ignoring POINTER_TYPE vs. > > REFERENCE_TYPE. */ > > && (TREE_TYPE (TREE_TYPE (TREE_OPERAND (node, 0))) > > == TREE_TYPE (TREE_TYPE (TREE_OPERAND (node, 1)))) > > && (TYPE_MODE (TREE_TYPE (TREE_OPERAND (node, 0))) > > == TYPE_MODE (TREE_TYPE (TREE_OPERAND (node, 1)))) > > && (TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (node, 0))) > > == TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (node, 1)))) > > /* Same value types ignoring qualifiers. */ > > && (TYPE_MAIN_VARIANT (TREE_TYPE (node)) > > == TYPE_MAIN_VARIANT > > (TREE_TYPE (TREE_TYPE (TREE_OPERAND (node, 1))))) > > && (!(flags & TDF_ALIAS) > > || MR_DEPENDENCE_CLIQUE (node) == 0)) > > > > ________________________________ > > From: Richard Biener <richard.guent...@gmail.com> > > Sent: Monday, January 3, 2022 5:49 AM > > To: Gary Oblock <g...@amperecomputing.com> > > Cc: gcc@gcc.gnu.org <gcc@gcc.gnu.org> > > Subject: Re: Why do these two trees print differently > > > > [EXTERNAL EMAIL NOTICE: This email originated from an external sender. > > Please be mindful of safe email handling and proprietary information > > protection practices.] > > > > > > On Wed, Dec 15, 2021 at 7:10 AM Gary Oblock via Gcc <gcc@gcc.gnu.org> wrote: > > > > > > This is one of those things that has always puzzled > > > me so I thought I break down and finally ask. > > > > > > There are two ways a memory reference (tree) prints: > > > > > > MEM[(struct arc_t *)_684].flow > > > > > > and > > > > > > _684->flow > > > > > > Poking under the hood of them, the tree codes and > > > operands are identical so what am I missing? > > > > Try dumping with -gimple, that should show you the difference. > > > > > > > > Thanks, > > > > > > Gary > > > > > > > > > CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, > > > is for the sole use of the intended recipient(s) and contains information > > > that is confidential and proprietary to Ampere Computing or its > > > subsidiaries. It is to be used solely for the purpose of furthering the > > > parties' business relationship. Any unauthorized review, copying, or > > > distribution of this email (or any attachments thereto) is strictly > > > prohibited. If you are not the intended recipient, please contact the > > > sender immediately and permanently delete the original and any copies of > > > this email and any attachments thereto.
