> -----Original Message----- > From: Richard Henderson [mailto:r...@redhat.com] > Sent: Thursday, November 06, 2014 4:23 PM > To: Zhenqiang Chen; 'Jan-Benedict Glaw'; Hartmut Penner; Ulrich Weigand; > Andreas Krebbel > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH, ifcvt] Allow CC mode if HAVE_cbranchcc4 (fix s390 build) > > On 11/06/2014 08:44 AM, Zhenqiang Chen wrote: > > Hi, > > > > The patch add runtime check to fix s390 build fail > > (https://gcc.gnu.org/ml/gcc-patches/2014-11/msg00050.html). > > > > And there is additional code to workaround s390 cstorecc4 issue. > > > > Bootstrap and no make check regression on X86-64. > > Build s390-linux-gnu and s390x-linux-gnu. > > > > I do not have env to run full s390 tests. Would anyone in the TO list > > help to run the s390 tests? > > > > Thanks! > > -Zhenqiang > > > > ChangeLog: > > 2014-11-06 Zhenqiang Chen <zhenqiang.c...@arm.com> > > > > * ifcvt.c (noce_emit_cmove, noce_get_alt_condition, > > noce_get_condition): > > Allow CC mode if HAVE_cbranchcc4. > > (noce_emit_store_flag): Change CC REG as cond_complex. > > > > diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index f4002f9..7f7b7c1 100644 > > --- a/gcc/ifcvt.c > > +++ b/gcc/ifcvt.c > > @@ -849,7 +849,10 @@ noce_emit_store_flag (struct noce_if_info > > *if_info, rtx x, int reversep, > > enum rtx_code code; > > > > cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode) > > - || ! general_operand (XEXP (cond, 1), VOIDmode)); > > + || ! general_operand (XEXP (cond, 1), VOIDmode) > > + /* For s390, CC REG is general_operand. But cstorecc4 > > only > > + handles CCZ1, which can not handle others like CCU. > > */ > > + || GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == > MODE_CC); > > > > I'd like to know more about this. This seems like a mistake in the backend. > > > +#ifdef HAVE_cbranchcc4 > > + if (GET_MODE_CLASS (GET_MODE (cmp_a)) != MODE_CC > > + || cmp_b != const0_rtx > > + || !(HAVE_cbranchcc4)) > > +#endif > > Please add > > #ifndef HAVE_cbranchcc4 > # define HAVE_cbranchcc4 > #endif > > at the top of ifcvt.c along with all of the others. Then use normal C tests > instead of preprocessor tests.
Thanks for the comment. > > + int allow_cc_mode = false; > > +#ifdef HAVE_cbranchcc4 > > + allow_cc_mode = HAVE_cbranchcc4; > > +#endif > > E.g. this becomes > > bool allow_cc_mode = HAVE_cbranchcc4; After adding HAVE_cbranchcc4, we can just use HAVE_cbranchcc4. No need to add a local variable allow_cc_mode. Here is the updated patch. diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index f4002f9..21f08c2 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -75,6 +75,10 @@ + 1) #endif +#ifndef HAVE_cbranchcc4 +#define HAVE_cbranchcc4 0 +#endif + #define IFCVT_MULTIPLE_DUMPS 1 #define NULL_BLOCK ((basic_block) NULL) @@ -1459,10 +1463,16 @@ noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code, end_sequence (); } - /* Don't even try if the comparison operands are weird. */ + /* Don't even try if the comparison operands are weird + except that the target supports cbranchcc4. */ if (! general_operand (cmp_a, GET_MODE (cmp_a)) || ! general_operand (cmp_b, GET_MODE (cmp_b))) - return NULL_RTX; + { + if (!(HAVE_cbranchcc4) + || GET_MODE_CLASS (GET_MODE (cmp_a)) != MODE_CC + || cmp_b != const0_rtx) + return NULL_RTX; + } #if HAVE_conditional_move unsignedp = (code == LTU || code == GEU @@ -1909,7 +1919,7 @@ noce_get_alt_condition (struct noce_if_info *if_info, rtx target, } cond = canonicalize_condition (if_info->jump, cond, reverse, - earliest, target, false, true); + earliest, target, HAVE_cbranchcc4, true); if (! cond || ! reg_mentioned_p (target, cond)) return NULL; @@ -2401,7 +2411,7 @@ noce_get_condition (rtx_insn *jump, rtx_insn **earliest, bool then_else_reversed /* Otherwise, fall back on canonicalize_condition to do the dirty work of manipulating MODE_CC values and COMPARE rtx codes. */ tmp = canonicalize_condition (jump, cond, reverse, earliest, - NULL_RTX, false, true); + NULL_RTX, HAVE_cbranchcc4, true); /* We don't handle side-effects in the condition, like handling REG_INC notes and making sure no duplicate conditions are emitted. */