| Message ID | 20140815115440.GS1784@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
Jakub, Is it important to have correct value for length attribute for Big Cores? As I new this attribute is used for code layout alignment. 2014-08-15 15:54 GMT+04:00 Jakub Jelinek <jakub@redhat.com>: > On Fri, Aug 15, 2014 at 03:45:33PM +0400, Yuri Rumyantsev wrote: >> gcc/ChangeLog >> 2014-08-15 Yuri Rumyantsev <ysrumyan@gmail.com> >> >> PR target/62011 >> * config/i386/i386-protos.h (ix86_avoid_false_dep_for_bm): New function >> prototype. >> * config/i386/i386.c (ix86_avoid_false_dep_for_bm): New function. >> * config/i386/i386.h (TARGET_AVOID_FALSE_DEP_FOR_BM) New macros. >> * config/i386/i386.md (ctz<mode>2, clz<mode>2_lzcnt, popcount<mode>2, >> *popcount<mode>2_cmp, *popcountsi2_cmp_zext): Output zeroing >> destination register for unary bit-manipulation instructions >> if required. >> * config/i386/x86-tune.def (X86_TUNE_AVOID_FALSE_DEP_FOR_BM): New. > > --- config/i386/i386.md (revision 213842) > +++ config/i386/i386.md (working copy) > @@ -12111,7 +12111,13 @@ > "" > { > if (TARGET_BMI) > - return "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; > + { > + if (ix86_avoid_false_dep_for_bm (insn, operands)) > + return "xor{<imodesuffix>}\t%0, %0\n\t" > + "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; > + else > + return "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; > + } > else if (optimize_function_for_size_p (cfun)) > ; > else if (TARGET_GENERIC) > > etc., this will make lenght attribute incorrect though. > > Jakub
--- config/i386/i386.md (revision 213842) +++ config/i386/i386.md (working copy) @@ -12111,7 +12111,13 @@ "" { if (TARGET_BMI) - return "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; + { + if (ix86_avoid_false_dep_for_bm (insn, operands)) + return "xor{<imodesuffix>}\t%0, %0\n\t" + "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; + else + return "tzcnt{<imodesuffix>}\t{%1, %0|%0, %1}"; + } else if (optimize_function_for_size_p (cfun)) ; else if (TARGET_GENERIC)