| Message ID | 87po6641x0.fsf@linaro.org |
|---|---|
| State | Accepted |
| Commit | 271134dd4894140542e38a4dcd8b4a07093d823a |
| Headers | show |
| Series | Avoid ICE for nested inductions (PR 83914) | expand |
On Fri, Jan 19, 2018 at 10:45 AM, Richard Sandiford <richard.sandiford@linaro.org> wrote: > This testcase ICEd because we converted the initial value of an > induction to the vector element type even for nested inductions. > This isn't necessary because the initial expression is vectorised > normally, and it meant that init_expr was no longer the original > statement operand by the time we called vect_get_vec_def_for_operand. > > Also, adding the conversion code here made the existing SLP conversion > redundant. > > It looks like something went wrong when rebasing the peeling via masks > work on top of the support for SLP reductions, sorry about that. > > Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu. > OK to install? Ok. Richard. > Richard > > > 2018-01-19 Richard Sandiford <richard.sandiford@linaro.org> > > gcc/ > PR tree-optimization/83914 > * tree-vect-loop.c (vectorizable_induction): Don't convert > init_expr or apply the peeling adjustment for inductions > that are nested within the vectorized loop. Remove redundant > conversion code. > > gcc/testsuite/ > PR tree-optimization/83914 > * gcc.dg/vect/pr83914.c: New test. > > Index: gcc/tree-vect-loop.c > =================================================================== > --- gcc/tree-vect-loop.c 2018-01-16 15:13:24.938622242 +0000 > +++ gcc/tree-vect-loop.c 2018-01-19 09:36:33.409191362 +0000 > @@ -7678,28 +7678,33 @@ vectorizable_induction (gimple *phi, > init_expr = PHI_ARG_DEF_FROM_EDGE (phi, > loop_preheader_edge (iv_loop)); > > - /* Convert the initial value and step to the desired type. */ > stmts = NULL; > - init_expr = gimple_convert (&stmts, TREE_TYPE (vectype), init_expr); > - step_expr = gimple_convert (&stmts, TREE_TYPE (vectype), step_expr); > - > - /* If we are using the loop mask to "peel" for alignment then we need > - to adjust the start value here. */ > - tree skip_niters = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo); > - if (skip_niters != NULL_TREE) > + if (!nested_in_vect_loop) > { > - if (FLOAT_TYPE_P (vectype)) > - skip_niters = gimple_build (&stmts, FLOAT_EXPR, TREE_TYPE (vectype), > - skip_niters); > - else > - skip_niters = gimple_convert (&stmts, TREE_TYPE (vectype), > - skip_niters); > - tree skip_step = gimple_build (&stmts, MULT_EXPR, TREE_TYPE (vectype), > - skip_niters, step_expr); > - init_expr = gimple_build (&stmts, MINUS_EXPR, TREE_TYPE (vectype), > - init_expr, skip_step); > + /* Convert the initial value to the desired type. */ > + tree new_type = TREE_TYPE (vectype); > + init_expr = gimple_convert (&stmts, new_type, init_expr); > + > + /* If we are using the loop mask to "peel" for alignment then we need > + to adjust the start value here. */ > + tree skip_niters = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo); > + if (skip_niters != NULL_TREE) > + { > + if (FLOAT_TYPE_P (vectype)) > + skip_niters = gimple_build (&stmts, FLOAT_EXPR, new_type, > + skip_niters); > + else > + skip_niters = gimple_convert (&stmts, new_type, skip_niters); > + tree skip_step = gimple_build (&stmts, MULT_EXPR, new_type, > + skip_niters, step_expr); > + init_expr = gimple_build (&stmts, MINUS_EXPR, new_type, > + init_expr, skip_step); > + } > } > > + /* Convert the step to the desired type. */ > + step_expr = gimple_convert (&stmts, TREE_TYPE (vectype), step_expr); > + > if (stmts) > { > new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); > @@ -7718,15 +7723,6 @@ vectorizable_induction (gimple *phi, > /* Enforced above. */ > unsigned int const_nunits = nunits.to_constant (); > > - /* Convert the init to the desired type. */ > - stmts = NULL; > - init_expr = gimple_convert (&stmts, TREE_TYPE (vectype), init_expr); > - if (stmts) > - { > - new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); > - gcc_assert (!new_bb); > - } > - > /* Generate [VF*S, VF*S, ... ]. */ > if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr))) > { > Index: gcc/testsuite/gcc.dg/vect/pr83914.c > =================================================================== > --- /dev/null 2018-01-19 09:30:49.543814408 +0000 > +++ gcc/testsuite/gcc.dg/vect/pr83914.c 2018-01-19 09:36:33.405191141 +0000 > @@ -0,0 +1,15 @@ > +/* { dg-do compile } */ > +/* { dg-additional-options "-O3" } */ > + > +struct s { struct s *ptrs[16]; } *a, *b; > +int c; > +void > +foo (int n) > +{ > + for (; n; a = b, n--) > + { > + b = a + 1; > + for (c = 8; c; c--) > + a->ptrs[c] = b; > + } > +}
Index: gcc/tree-vect-loop.c =================================================================== --- gcc/tree-vect-loop.c 2018-01-16 15:13:24.938622242 +0000 +++ gcc/tree-vect-loop.c 2018-01-19 09:36:33.409191362 +0000 @@ -7678,28 +7678,33 @@ vectorizable_induction (gimple *phi, init_expr = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (iv_loop)); - /* Convert the initial value and step to the desired type. */ stmts = NULL; - init_expr = gimple_convert (&stmts, TREE_TYPE (vectype), init_expr); - step_expr = gimple_convert (&stmts, TREE_TYPE (vectype), step_expr); - - /* If we are using the loop mask to "peel" for alignment then we need - to adjust the start value here. */ - tree skip_niters = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo); - if (skip_niters != NULL_TREE) + if (!nested_in_vect_loop) { - if (FLOAT_TYPE_P (vectype)) - skip_niters = gimple_build (&stmts, FLOAT_EXPR, TREE_TYPE (vectype), - skip_niters); - else - skip_niters = gimple_convert (&stmts, TREE_TYPE (vectype), - skip_niters); - tree skip_step = gimple_build (&stmts, MULT_EXPR, TREE_TYPE (vectype), - skip_niters, step_expr); - init_expr = gimple_build (&stmts, MINUS_EXPR, TREE_TYPE (vectype), - init_expr, skip_step); + /* Convert the initial value to the desired type. */ + tree new_type = TREE_TYPE (vectype); + init_expr = gimple_convert (&stmts, new_type, init_expr); + + /* If we are using the loop mask to "peel" for alignment then we need + to adjust the start value here. */ + tree skip_niters = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo); + if (skip_niters != NULL_TREE) + { + if (FLOAT_TYPE_P (vectype)) + skip_niters = gimple_build (&stmts, FLOAT_EXPR, new_type, + skip_niters); + else + skip_niters = gimple_convert (&stmts, new_type, skip_niters); + tree skip_step = gimple_build (&stmts, MULT_EXPR, new_type, + skip_niters, step_expr); + init_expr = gimple_build (&stmts, MINUS_EXPR, new_type, + init_expr, skip_step); + } } + /* Convert the step to the desired type. */ + step_expr = gimple_convert (&stmts, TREE_TYPE (vectype), step_expr); + if (stmts) { new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); @@ -7718,15 +7723,6 @@ vectorizable_induction (gimple *phi, /* Enforced above. */ unsigned int const_nunits = nunits.to_constant (); - /* Convert the init to the desired type. */ - stmts = NULL; - init_expr = gimple_convert (&stmts, TREE_TYPE (vectype), init_expr); - if (stmts) - { - new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); - gcc_assert (!new_bb); - } - /* Generate [VF*S, VF*S, ... ]. */ if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr))) { Index: gcc/testsuite/gcc.dg/vect/pr83914.c =================================================================== --- /dev/null 2018-01-19 09:30:49.543814408 +0000 +++ gcc/testsuite/gcc.dg/vect/pr83914.c 2018-01-19 09:36:33.405191141 +0000 @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-O3" } */ + +struct s { struct s *ptrs[16]; } *a, *b; +int c; +void +foo (int n) +{ + for (; n; a = b, n--) + { + b = a + 1; + for (c = 8; c; c--) + a->ptrs[c] = b; + } +}