From: Vladimir Mezentsev <vladimir.mezent...@oracle.com> FMA (floating-point multiply-add) instructions are supported on aarch64. These instructions can produce different result if two operations executed separately. -ffp-contract=off doesn't allow the FMA instructions.
Tested on aarch64-unknown-linux-gnu. No regression. Two failed tests now passed. ChangeLog: 2017-10-25 Vladimir Mezentsev <vladimir.mezent...@oracle.com> PR libgcc/59714 * libgcc/Makefile.in: Add -ffp-contract=off --- libgcc/Makefile.in | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in index a1a392d..f313556 100644 --- a/libgcc/Makefile.in +++ b/libgcc/Makefile.in @@ -455,6 +455,14 @@ ifeq ($(LIB2_SIDITI_CONV_FUNCS),) lib2funcs += $(subst XX,di,$(dwfloatfuncs)) endif +# Disable FMA (floating-point multiply-add) instructions for complex division. +# These instructions can produce different result if two operations executed separately. +LIBGCC2_FFP_CONTRAST_CFLAGS = -ffp-contract=off +LIB2_DIV3_FUNCS = _divdc3 _divhc3 _divsc3 +lib2-div3-o = $(patsubst %,%$(objext),$(LIB2_DIV3_FUNCS)) +lib2-div3-s-o = $(patsubst %,%_s$(objext),$(LIB2_DIV3_FUNCS)) +$(lib2-div3-o) $(lib2-div3-s-o): LIBGCC2_CFLAGS += $(LIBGCC2_FFP_CONTRAST_CFLAGS) + # These might cause a divide overflow trap and so are compiled with # unwinder info. LIB2_DIVMOD_FUNCS = _divdi3 _moddi3 _divmoddi4 \ -- 1.8.3.1
