[LLVMbugs] [Bug 14529] New: clang should recognize C99 complex extract functions

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=14529

             Bug #: 14529
           Summary: clang should recognize C99 complex extract functions
           Product: clang
           Version: trunk
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: -New Bugs
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: daniel at zuster.org
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified


We should pattern match C99 complex functions, like ICC does. The following
example should compile down to just trivial load instructions:
--
$ cat t2.c
#include <complex.h>

double f0(double complex z) {
  return creal(z);
}

long double f1(long double complex z) {
  return creall(z);
}

float f2(float complex z) {
  return crealf(z);
}

double f3(double complex z) {
  return cimag(z);
}

long double f4(long double complex z) {
  return cimagl(z);
}

float f5(float complex z) {
  return cimagf(z);
}

$ clang -O3 -S -o - t2.c
    .section    __TEXT,__text,regular,pure_instructions
    .globl    _f0
    .align    4, 0x90
_f0:                                    ## @f0
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp2:
    .cfi_def_cfa_offset 16
Ltmp3:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp4:
    .cfi_def_cfa_register %rbp
    popq    %rbp
    jmp    _creal                  ## TAILCALL
    .cfi_endproc

    .globl    _f1
    .align    4, 0x90
_f1:                                    ## @f1
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp7:
    .cfi_def_cfa_offset 16
Ltmp8:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp9:
    .cfi_def_cfa_register %rbp
    subq    $64, %rsp
    fldt    32(%rbp)
    fldt    16(%rbp)
    fstpt    -32(%rbp)
    fstpt    -16(%rbp)
    movaps    -32(%rbp), %xmm0
    movaps    -16(%rbp), %xmm1
    movaps    %xmm1, 16(%rsp)
    movaps    %xmm0, (%rsp)
    callq    _creall
    addq    $64, %rsp
    popq    %rbp
    ret
    .cfi_endproc

    .globl    _f2
    .align    4, 0x90
_f2:                                    ## @f2
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp12:
    .cfi_def_cfa_offset 16
Ltmp13:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp14:
    .cfi_def_cfa_register %rbp
    popq    %rbp
    jmp    _crealf                 ## TAILCALL
    .cfi_endproc

    .globl    _f3
    .align    4, 0x90
_f3:                                    ## @f3
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp17:
    .cfi_def_cfa_offset 16
Ltmp18:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp19:
    .cfi_def_cfa_register %rbp
    popq    %rbp
    jmp    _cimag                  ## TAILCALL
    .cfi_endproc

    .globl    _f4
    .align    4, 0x90
_f4:                                    ## @f4
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp22:
    .cfi_def_cfa_offset 16
Ltmp23:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp24:
    .cfi_def_cfa_register %rbp
    subq    $64, %rsp
    fldt    32(%rbp)
    fldt    16(%rbp)
    fstpt    -32(%rbp)
    fstpt    -16(%rbp)
    movaps    -32(%rbp), %xmm0
    movaps    -16(%rbp), %xmm1
    movaps    %xmm1, 16(%rsp)
    movaps    %xmm0, (%rsp)
    callq    _cimagl
    addq    $64, %rsp
    popq    %rbp
    ret
    .cfi_endproc

    .globl    _f5
    .align    4, 0x90
_f5:                                    ## @f5
    .cfi_startproc
## BB#0:
    pushq    %rbp
Ltmp27:
    .cfi_def_cfa_offset 16
Ltmp28:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp29:
    .cfi_def_cfa_register %rbp
    popq    %rbp
    jmp    _cimagf                 ## TAILCALL
    .cfi_endproc


.subsections_via_symbols

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