[Bug jit/64020] jit misses sin/cos optimizations

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64020

--- Comment #2 from dmalcolm at gcc dot gnu.org ---
For reference, both at -O3, based on r217939:

./cc1 of

#include <math.h>

int
test_of_builtin_trig (double theta)
{
  return 2 * sin (theta) * cos (theta);
}

generates:

test_of_builtin_trig:
.LFB3:
        .cfi_startproc
        subq    $24, %rsp
        .cfi_def_cfa_offset 32
        leaq    8(%rsp), %rdi
        movq    %rsp, %rsi
        call    sincos
        movsd   8(%rsp), %xmm0
        addsd   %xmm0, %xmm0
        mulsd   (%rsp), %xmm0
        addq    $24, %rsp
        .cfi_def_cfa_offset 8
        cvttsd2si       %xmm0, %eax
        ret
        .cfi_endproc

[would it be even better to optimize this to just a sin (2 * theta) ?]

whereas the jit test generates:

test_of_builtin_trig:
.LFB32:
    .cfi_startproc
.LVL4:
.L37:
    subq    $24, %rsp
    .cfi_def_cfa_offset 32
    movsd    %xmm0, 8(%rsp)
    call    sin@PLT
.LVL5:
    movsd    8(%rsp), %xmm1
    movsd    %xmm0, (%rsp)
    movapd    %xmm1, %xmm0
    call    cos@PLT
.LVL6:
    mulsd    (%rsp), %xmm0
    addq    $24, %rsp
    .cfi_def_cfa_offset 8
    addsd    %xmm0, %xmm0
    ret
    .cfi_endproc