clang/test/CodeGen/builtin-nan-legacy.c

   1 // RUN: %clang -target mipsel-unknown-linux -mnan=legacy -emit-llvm -S %s -o - | FileCheck %s
   2 // CHECK: float 0x7FFC000000000000, float 0x7FF8000000000000
   3 // CHECK: double 0x7FF4000000000000, double 0x7FF8000000000000
   4
   5 // The first line shows an unintended consequence.
   6 // __builtin_nan() creates a legacy QNAN double with an empty payload
   7 // (the first bit of the significand is clear to indicate quiet, so
   8 // the second bit of the payload is set to maintain NAN-ness).
   9 // The value is then truncated, but llvm::APFloat does not know about
  10 // the inverted quiet bit, so it sets the first bit on conversion
  11 // to indicate 'quiet' independently of the setting in clang.
  12
  13 float f[] = {
  14   __builtin_nan(""),
  15   __builtin_nans(""),
  16 };
  17
  18 double d[] = {
  19   __builtin_nan(""),
  20   __builtin_nans(""),
  21 };