On Sun, Jul 24, 2011 at 2:34 PM, Uros Bizjak <ubiz...@gmail.com> wrote: > On Sat, Jul 23, 2011 at 3:57 PM, H.J. Lu <hjl.to...@gmail.com> wrote: > >>>> This patch adds x32 LEA insn support. The main issue is >>>> >>>> gen_lowpart (Pmode, operands[1]); >>>> >>>> doesn't work on symbol. This patch avoids it. >>>> >>>> Also we shouldn't generate 32bit store with x32 PIC source. >>>> >>>> Any comments? > > You are not fixing the core of the problem... this is why you need so > much hacks and kludges at various places (some w.r.t. -fPIC already > existed, see the patch). Above, you correctly identified the problem, > so let's avoid gen_lowpart on SImode operands by not calling it > anymore. > > Attached patch effectively rewrites LEA handling. The trick is, that > instead of using Pmode operations in addresses, we use either SImode > or DImode operations to calculate the address on 64bit targets. Up to > now, address calculations strictly used Pmode, so SImode on 32bit > targets and DImode on 64bit targets. Recent patches to > ix86_decompose_address and ix86_legitimate_address_p relaxed this > requirement. > > Attached patch changes LEA patterns and LEA splitters to accept > addresses, calculated with either SImode or DImode operations.This > means, that on x64 targets, we don't use gen_lowpart on SImode > operands anymore. Since symbol references on x32 are in SImode, this > solves the problem. The patch also avoids generating SImode subregs of > DImode addresses and DImode zero_extends of SImode addresses, since > LEA insn does this for us automatically. > > Please also note the change to ix86_print_operand_address. To avoid > addr32 prefixes, we can force registers in DImode on 64bit targets > without any problems. On x32, we can investigate, if this change > avoids unnecessary LEAs (for PR 49781, patched gcc genrates 6 vs. 8).
The testcase won't compile since PIC doesn't work: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49833 > Also, we can investigate the effect of addr32 on benchmarks. We should get x32 working on trunk first. We will improve its performance later. > Patched gcc also fixes all testcases from PR 47381. > > 2011-07-24 Uros Bizjak <ubiz...@gmail.com> > > PR target/47381 > * config/i386/i386.md (*lea_1): Use SWI48 mode iterator. > (*lea_1_zext): New insn pattern. > (add->lea splitter): Check operand modes in insn constraint. Extend > operands less than SImode wide to SImode. > (add->lea zext splitter): Do not extend operands to DImode. > (*lea_general_1): Handle only QImode and HImode operands. > (*lea_general_2): Ditto. > (*lea_general_3): Ditto. > (*lea_general_1_zext): Remove. > (*lea_general_2_zext): Ditto. > (*lea_general_3_zext): Ditto. > (*lea_general_4): Check operand modes in insn constraint. Extend > operands less than SImode wide to SImode. > (ashift->lea splitter): Ditto. > * config/i386/i386.md (ix86_print_operand_address): Print address > registers with 'q' modifier on 64bit targets. > > Patch was bootstrapped and regression tested on x86_64-pc-linux-gnu > {,-m32} with no regressions. H.J., can you please test it on x32? On x32, it failed: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49832 > BTW: -fPIC is not yet implemented on trunk and still fails there with > an (unrelated) error, I didn't check x32 branch. > This could be: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49833 Thanks. -- H.J.
