[PATCH] D69876: Allow output constraints on "asm goto"

[Bill Wendling via Phabricator via cfe-commits]

void added a comment.

I'm not getting the `Undefined temporary symbol` in your example (even with 
optimizations):

  [morbo@fawn:llvm-project] cat ../bug.c
  void baz(void) {
      int y;
      asm volatile goto ("mov 42, %0; ja %1": "=d"(y) ::: quux);
      asm volatile goto ("mov 42, %0; ja %1": "=c"(y) ::: quux);
      return;
  quux:
      return;
  }
  [morbo@fawn:llvm-project] clang -o - -S ../bug.c
        .text
        .file   "bug.c"
        .globl  baz                     # -- Begin function baz
        .p2align        4, 0x90
        .type   baz,@function
  baz:                                    # @baz
        .cfi_startproc
  # %bb.0:                                # %entry
        pushq   %rbp
        .cfi_def_cfa_offset 16
        .cfi_offset %rbp, -16
        movq    %rsp, %rbp
        .cfi_def_cfa_register %rbp
        #APP
        movl    42, %edx
        ja      .Ltmp00
        #NO_APP
        movl    %edx, -8(%rbp)          # 4-byte Spill
        jmp     .LBB0_1
  .LBB0_1:                                # %asm.fallthrough
        movl    -8(%rbp), %eax          # 4-byte Reload
        movl    %eax, -4(%rbp)
        #APP
        movl    42, %ecx
        ja      .Ltmp00
        #NO_APP
        movl    %ecx, -12(%rbp)         # 4-byte Spill
        jmp     .LBB0_2
  .LBB0_2:                                # %asm.fallthrough1
        movl    -12(%rbp), %eax         # 4-byte Reload
        movl    %eax, -4(%rbp)
        jmp     .LBB0_4
  .Ltmp0:                                 # Block address taken
  .LBB0_3:                                # %quux
        jmp     .LBB0_4
  .LBB0_4:                                # %return
        popq    %rbp
        .cfi_def_cfa %rsp, 8
        retq
  .Lfunc_end0:
        .size   baz, .Lfunc_end0-baz
        .cfi_endproc
                                          # -- End function
        .ident  "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 
5b71b09a54edbb20900e6d13de35d2592f788330)"
        .section        ".note.GNU-stack","",@progbits
        .addrsig
        .addrsig_sym baz


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69876/new/

https://reviews.llvm.org/D69876



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