[test-suite] r181270 - Force ffp-contract=off on PowerPC/Linux

Hal Finkel hfinkel at anl.gov
Mon May 6 16:03:52 PDT 2013


Author: hfinkel
Date: Mon May  6 18:03:52 2013
New Revision: 181270

URL: http://llvm.org/viewvc/llvm-project?rev=181270&view=rev
Log:
Force ffp-contract=off on PowerPC/Linux

In order for the test-suite outputs to match the reference outputs we need to
specify -ffp-contract=off. Not only does extra FMA precision cause differences
between the outputs and the reference outputs, but also between our output and
that of gcc (because the two compilers sometimes make slightly different
contraction choices). Fortunately, providing -ffp-contract=off to both
compilers reveals agreement. Older versions of gcc did not support
-ffp-contract, and if using such a version, you'll need to use the reference
outputs (which you should be able to do now).

Modified:
    test-suite/trunk/Makefile.config.in

Modified: test-suite/trunk/Makefile.config.in
URL: http://llvm.org/viewvc/llvm-project/test-suite/trunk/Makefile.config.in?rev=181270&r1=181269&r2=181270&view=diff
==============================================================================
--- test-suite/trunk/Makefile.config.in (original)
+++ test-suite/trunk/Makefile.config.in Mon May  6 18:03:52 2013
@@ -139,6 +139,15 @@ ifeq ($(ARCH),THUMB)
 TEST_TARGET_FLAGS += -mthumb
 endif
 
+# PowerPC/Linux needs -ffp-contract=off so that:
+#     The outputs can be compared to gcc.
+#     The outputs match the reference outputs.
+ifeq ($(ARCH),PowerPC)
+ifeq ($(TARGET_OS),Linux)
+TEST_TARGET_FLAGS += -ffp-contract=off
+endif
+endif
+
 #
 # Provide variables specific to llvm-test
 #





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