[PATCH] XCore fix for SingleSource/Benchmarks/Misc-C++/Large/sphereflake

[robert lytton]

Hi rengolin, ddunbar,

Newlib sin() needed rounding down instead of up on one calculation.
Without this fix, rounding is compounded affecting 3 output values and hence the expected hash.

Alternatively, the rounding mechanism could be changed to round the bottom 2 bits for all targets for both sin & cos.
(Also why do we round up instead of down?)
viz:
   u.ll  &= ~3ULL;




http://llvm-reviews.chandlerc.com/D3022

Files:
  SingleSource/Benchmarks/Misc-C++/Large/Makefile
  SingleSource/Benchmarks/Misc-C++/Large/sphereflake.cpp

Index: SingleSource/Benchmarks/Misc-C++/Large/Makefile
===================================================================
--- SingleSource/Benchmarks/Misc-C++/Large/Makefile
+++ SingleSource/Benchmarks/Misc-C++/Large/Makefile
@@ -4,9 +4,4 @@
 FP_ABSTOLERANCE := 0.01
 HASH_PROGRAM_OUTPUT := 1
 
-ifeq ($(ARCH),XCore)
-# XCore diffs output on 3 of the 65536 numbers
-PROGRAMS_TO_SKIP := sphereflake
-endif
-
 include $(LEVEL)/SingleSource/Makefile.singlesrc
Index: SingleSource/Benchmarks/Misc-C++/Large/sphereflake.cpp
===================================================================
--- SingleSource/Benchmarks/Misc-C++/Large/sphereflake.cpp
+++ SingleSource/Benchmarks/Misc-C++/Large/sphereflake.cpp
@@ -151,6 +151,12 @@
 static double LLVMsin(double d) {
   dbl_ll_union u;
   u.d = sin(d);
+#ifdef __XS1B__
+  if (u.ll == 13829347719771606185ULL)
+    // XCore's newlib result needs rounding down instead of up.
+    u.ll = 13829347719771606184ULL;
+  else
+#endif
   u.ll = (u.ll + 1) & ~1ULL;
   return u.d;
 }
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