[Bug tree-optimization/69827] New: [5 Regression] sincos not done

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69827

            Bug ID: 69827
           Summary: [5 Regression] sincos not done
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tkoenig at gcc dot gnu.org
  Target Milestone: ---

The following code does not produce a call to sincos even with
-ffast-math -O3.

I think this should be happening since PR 30038, so am I tentatively
marking this as a regression.  Not sure about current trunk,
hope to be able to check soon.

$ cat foo.c
#include <math.h>

void foo(double t, double *x, double *y)
{
    *y = sin(t);
    *x = cos(t);
}

$ gcc -S -O3 -ffast-math foo.c

$ cat foo.s
        .file   "foo.c"
        .section        .text.unlikely,"x"
.LCOLDB0:
        .text
.LHOTB0:
        .p2align 4,,15
        .globl  foo
        .def    foo;    .scl    2;      .type   32;     .endef
        .seh_proc       foo
foo:
        pushq   %rsi
        .seh_pushreg    %rsi
        pushq   %rbx
        .seh_pushreg    %rbx
        subq    $56, %rsp
        .seh_stackalloc 56
        movaps  %xmm6, 32(%rsp)
        .seh_savexmm    %xmm6, 32
        .seh_endprologue
        movapd  %xmm0, %xmm6
        movq    %r8, %rsi
        movq    %rdx, %rbx
        call    sin
        movsd   %xmm0, (%rsi)
        movapd  %xmm6, %xmm0
        call    cos
        nop
        movaps  32(%rsp), %xmm6
        movsd   %xmm0, (%rbx)
        addq    $56, %rsp
        popq    %rbx
        popq    %rsi
        ret
        .seh_endproc
        .section        .text.unlikely,"x"
.LCOLDE0:
        .text
.LHOTE0:
        .ident  "GCC: (GNU) 5.3.0"
        .def    sin;    .scl    2;      .type   32;     .endef
        .def    cos;    .scl    2;      .type   32;     .endef

This works as expected:

$ cat bar.c
void bar(double t, double *x, double *y)
{
    __builtin_sincos(t, x, y);
    *x = *x + 1.;
}

$ gcc -O3 -S bar.c

$ cat bar.s
        .file   "bar.c"
        .section        .text.unlikely,"x"
.LCOLDB1:
        .text
.LHOTB1:
        .p2align 4,,15
        .globl  bar
        .def    bar;    .scl    2;      .type   32;     .endef
        .seh_proc       bar
bar:
        pushq   %rbx
        .seh_pushreg    %rbx
        subq    $32, %rsp
        .seh_stackalloc 32
        .seh_endprologue
        movq    %rdx, %rbx
        call    sincos
        movsd   .LC0(%rip), %xmm0
        addsd   (%rbx), %xmm0
        movsd   %xmm0, (%rbx)
        addq    $32, %rsp
        popq    %rbx
        ret
        .seh_endproc
        .section        .text.unlikely,"x"
.LCOLDE1:
        .text
.LHOTE1:
        .section .rdata,"dr"
        .align 8
.LC0:
        .long   0
        .long   1072693248
        .ident  "GCC: (GNU) 5.3.0"
        .def    sincos; .scl    2;      .type   32;     .endef




$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-cygwin/5.3.0/lto-wrapper.exe
Target: x86_64-unknown-cygwin
Configured with: ../gcc-5.3.0/configure --enable-languages=c,c++,fortran,lto
--enable-shared --enable-shared-libgcc --enable-static
--enable-version-specific-runtime-libs --enable-bootstrap --enable-__cxa_atexit
--with-dwarf2 --with-tune=generic --enable-languages=c,c++,fortran,lto
--enable-graphite --enable-threads=posix --enable-libatomic --enable-libgomp
--disable-libitm --enable-libquadmath --enable-libquadmath-support
--enable-libssp --disable-symvers --with-gnu-ld --with-gnu-as
--with-cloog-include=/usr/include/cloog-isl --without-libiconv-prefix
--without-libintl-prefix --with-system-zlib --enable-linker-build-id
Thread model: posix
gcc version 5.3.0 (GCC)