The following fixes mishandling of widening invariant comparisons in vect_is_simple_cond which isn't supported for SLP code generation.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk, queued for backports. Richard. 2018-05-22 Richard Biener <rguent...@suse.de> PR tree-optimization/85863 * tree-vect-stmts.c (vect_is_simple_cond): Only widen invariant comparisons when vectype is specified. (vectorizable_condition): Do not specify vectype for vect_is_simple_cond when SLP vectorizing. * gfortran.fortran-torture/compile/pr85863.f: New testcase. Index: gcc/tree-vect-stmts.c =================================================================== --- gcc/tree-vect-stmts.c (revision 260499) +++ gcc/tree-vect-stmts.c (working copy) @@ -8661,7 +8661,7 @@ vect_is_simple_cond (tree cond, vec_info *comp_vectype = vectype1 ? vectype1 : vectype2; /* Invariant comparison. */ - if (! *comp_vectype) + if (! *comp_vectype && vectype) { tree scalar_type = TREE_TYPE (lhs); /* If we can widen the comparison to match vectype do so. */ @@ -8773,7 +8773,7 @@ vectorizable_condition (gimple *stmt, gi else_clause = gimple_assign_rhs3 (stmt); if (!vect_is_simple_cond (cond_expr, stmt_info->vinfo, - &comp_vectype, &dts[0], vectype) + &comp_vectype, &dts[0], slp_node ? NULL : vectype) || !comp_vectype) return false; Index: gcc/testsuite/gfortran.fortran-torture/compile/pr85863.f =================================================================== --- gcc/testsuite/gfortran.fortran-torture/compile/pr85863.f (nonexistent) +++ gcc/testsuite/gfortran.fortran-torture/compile/pr85863.f (working copy) @@ -0,0 +1,22 @@ +! { dg-do compile } +! { dg-additional-options "-ffast-math -ftree-vectorize" } + SUBROUTINE SOBOOK(MHSO,HSOMAX,MS) + IMPLICIT DOUBLE PRECISION(A-H,O-Z) + COMPLEX*16 HSOT,HSO1(2) + PARAMETER (ZERO=0.0D+00,TWO=2.0D+00) + DIMENSION SOL1(3,2),SOL2(3) + CALL FOO(SOL1,SOL2) + SQRT2=SQRT(TWO) + DO IH=1,MHSO + IF(MS.EQ.0) THEN + HSO1(IH) = DCMPLX(ZERO,-SOL1(3,IH)) + HSOT = DCMPLX(ZERO,-SOL2(3)) + ELSE + HSO1(IH) = DCMPLX(-SOL1(2,IH),SOL1(1,IH))/SQRT2 + HSOT = DCMPLX(-SOL2(2),SOL2(1))/SQRT2 + ENDIF + ENDDO + HSOT=HSOT+HSO1(1) + HSOMAX=MAX(HSOMAX,ABS(HSOT)) + RETURN + END