On Wed, Jun 21, 2023 at 11:32 AM Richard Sandiford <richard.sandif...@arm.com> wrote: > > Richard Sandiford <richard.sandif...@arm.com> writes: > > Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> writes: > >> On Fri, Jun 2, 2023 at 3:01 AM liuhongt via Gcc-patches > >> <gcc-patches@gcc.gnu.org> wrote: > >>> > >>> We have already use intermidate type in case WIDEN, but not for NONE, > >>> this patch extended that. > >>> > >>> I didn't do that in pattern recog since we need to know whether the > >>> stmt belongs to any slp_node to decide the vectype, the related optabs > >>> are checked according to vectype_in and vectype_out. For non-slp case, > >>> vec_pack/unpack are always used when lhs has different size from rhs, > >>> for slp case, sometimes vec_pack/unpack is used, somethings > >>> direct conversion is used. > >>> > >>> Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. > >>> Ok for trunk? > >>> > >>> gcc/ChangeLog: > >>> > >>> PR target/110018 > >>> * tree-vect-stmts.cc (vectorizable_conversion): Use > >>> intermiediate integer type for float_expr/fix_trunc_expr when > >>> direct optab is not existed. > >>> > >>> gcc/testsuite/ChangeLog: > >>> > >>> * gcc.target/i386/pr110018-1.c: New test. > >>> --- > >>> gcc/testsuite/gcc.target/i386/pr110018-1.c | 94 ++++++++++++++++++++++ > >>> gcc/tree-vect-stmts.cc | 56 ++++++++++++- > >>> 2 files changed, 149 insertions(+), 1 deletion(-) > >>> create mode 100644 gcc/testsuite/gcc.target/i386/pr110018-1.c > >>> > >>> diff --git a/gcc/testsuite/gcc.target/i386/pr110018-1.c > >>> b/gcc/testsuite/gcc.target/i386/pr110018-1.c > >>> new file mode 100644 > >>> index 00000000000..b1baffd7af1 > >>> --- /dev/null > >>> +++ b/gcc/testsuite/gcc.target/i386/pr110018-1.c > >>> @@ -0,0 +1,94 @@ > >>> +/* { dg-do compile } */ > >>> +/* { dg-options "-mavx512fp16 -mavx512vl -O2 -mavx512dq" } */ > >>> +/* { dg-final { scan-assembler-times {(?n)vcvttp[dsh]2[dqw]} 5 } } */ > >>> +/* { dg-final { scan-assembler-times {(?n)vcvt[dqw]*2p[dsh]} 5 } } */ > >>> + > >>> +void > >>> +foo (double* __restrict a, char* b) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> +} > >>> + > >>> +void > >>> +foo1 (float* __restrict a, char* b) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> +} > >>> + > >>> +void > >>> +foo2 (_Float16* __restrict a, char* b) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> + a[4] = b[4]; > >>> + a[5] = b[5]; > >>> + a[6] = b[6]; > >>> + a[7] = b[7]; > >>> +} > >>> + > >>> +void > >>> +foo3 (double* __restrict a, short* b) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> +} > >>> + > >>> +void > >>> +foo4 (float* __restrict a, char* b) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> +} > >>> + > >>> +void > >>> +foo5 (double* __restrict b, char* a) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> +} > >>> + > >>> +void > >>> +foo6 (float* __restrict b, char* a) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> +} > >>> + > >>> +void > >>> +foo7 (_Float16* __restrict b, char* a) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> + a[4] = b[4]; > >>> + a[5] = b[5]; > >>> + a[6] = b[6]; > >>> + a[7] = b[7]; > >>> +} > >>> + > >>> +void > >>> +foo8 (double* __restrict b, short* a) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> +} > >>> + > >>> +void > >>> +foo9 (float* __restrict b, char* a) > >>> +{ > >>> + a[0] = b[0]; > >>> + a[1] = b[1]; > >>> + a[2] = b[2]; > >>> + a[3] = b[3]; > >>> +} > >>> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc > >>> index bd3b07a3aa1..1118c89686d 100644 > >>> --- a/gcc/tree-vect-stmts.cc > >>> +++ b/gcc/tree-vect-stmts.cc > >>> @@ -5162,6 +5162,49 @@ vectorizable_conversion (vec_info *vinfo, > >>> return false; > >>> if (supportable_convert_operation (code, vectype_out, vectype_in, > >>> &code1)) > >>> break; > >> > >> A comment would be nice here. Like > >> > >> /* For conversions between float and smaller integer types try whether > >> we can > >> use intermediate signed integer types to support the conversion. */ > >> > >>> + if ((code == FLOAT_EXPR > >>> + && GET_MODE_SIZE (lhs_mode) > GET_MODE_SIZE (rhs_mode)) > >>> + || (code == FIX_TRUNC_EXPR > >>> + && GET_MODE_SIZE (rhs_mode) > GET_MODE_SIZE (lhs_mode))) > > > > Is the FIX_TRUNC_EXPR case safe without some flag? > > > > #include <stdint.h> > > int32_t x = (int32_t)0x1.0p32; > > int32_t y = (int32_t)(int64_t)0x1.0p32; > > > > sets x to 2147483647 and y to 0.
Hmm, good question. GENERIC has a direct truncation to unsigned char for example, the C standard generally says if the integral part cannot be represented then the behavior is undefined. So I think we should be safe here (0x1.0p32 doesn't fit an int). > Also, I think multi_step_cvt should influence the costs, since at > the moment we cost one statement but generate two. This makes a > difference for SVE with VECT_COMPARE_COSTS. Would changing it to: > > vect_model_simple_cost (vinfo, stmt_info, > ncopies * (multi_step_cvt + 1), > dt, ndts, slp_node, > cost_vec); > > be OK? Yeah, I guess so. > There again, I wonder if we should handle this using patterns instead. > That makes both conversions explicit and therefore easier to cost. But we don't do this for the other multi-step conversions either ... but sure, I also suggested that but the complaint was that with BB SLP this would get us a vector type with off lanes? > E.g. for SVE, an integer extension is free if the source is a load, > and we do try to model that. But it's difficult to handle if the > conversion is only implicit. In the distant future I hope that vectorizable_conversion will upon analysis produce an SLP sub-graph for the suggested code generation which we'd then cost. My current idea is to get this part live before switching the analysis to all-SLP because it "seems" easier (fingers crossing). Still I'm struggling to even find time to start that effort. Richard. > > Thanks, > Richard