[LLVMbugs] [Bug 9557] New: return value ignored

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=9557

           Summary: return value ignored
           Product: clang
           Version: trunk
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: -New Bugs
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: ahatanak at gmail.com
                CC: llvmbugs at cs.uiuc.edu


In the following example, main function in generated bit code does not return
0.

# .c file
/* Verify whether math functions are simplified.  */
double sin(double);
double floor(double);
float
t(float a)
{
  return sin(a);
}
float
q(float a)
{
  return floor(a);
}
double
q1(float a)
{
  return floor(a);
}
main()
{
#ifdef __OPTIMIZE__
  if (t(0)!=0)
    abort ();
  if (q(0)!=0)
    abort ();
  if (q1(0)!=0)
    abort ();
#endif
  return 0;
}
__attribute__ ((noinline))
double
floor(double a)
{
  abort ();
}
__attribute__ ((noinline))
float
floorf(float a)
{
  return a;
}
__attribute__ ((noinline))
double
sin(double a)
{
  abort ();
}
__attribute__ ((noinline))
float
sinf(float a)
{
  return a;
}

# .ll file generated 
# clang tests-c/20030125-1.c -D __OPTIMIZE__=1 -emit-llvm -O1 -S -o -

; ModuleID = 'tests-c/20030125-1.c'
target datalayout =
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
target triple = "i386-pc-linux-gnu"

define float @t(float %a) noreturn nounwind readnone {
entry:
  unreachable
}

define double @sin(double %a) noreturn nounwind readnone noinline {
entry:
  tail call void @abort() noreturn nounwind
  unreachable
}

define float @q(float %a) noreturn nounwind {
entry:
  %call = tail call double @floor(double undef)
  unreachable
}

define double @floor(double %a) noreturn nounwind noinline {
entry:
  tail call void @abort() noreturn nounwind
  unreachable
}

define double @q1(float %a) noreturn nounwind {
entry:
  %call = tail call double @floor(double undef)
  unreachable
}

define i32 @main() nounwind {
entry:
  unreachable
}

declare void @abort() noreturn

define float @floorf(float %a) nounwind readnone noinline {
entry:
  ret float %a
}

define float @sinf(float %a) nounwind readnone noinline {
entry:
  ret float %a
}

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