https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69124
Bug ID: 69124 Summary: arm miss compiled code since gcc 5 Product: gcc Version: 5.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: gcc at breakpoint dot cc Target Milestone: --- Host: arm-linux-gnueabihf Target: arm-linux-gnueabihf Build: arm-linux-gnueabihf Created attachment 37213 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37213&action=edit test case, fp_mul_comba_32.c Attached a testcase that miss compiles on ARM since gcc-5 (Debian gcc, built with --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard). gcc -o fp_mul fp_mul_comba_32.c -O2 -Wall -Wextra -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations ./fp_mul 27 0x0a7d8ff8 != 0xce804437 28 0x1c8a1f70 != 0x1c8a1f6f -> 3 I don't see this with problem with -O1, or arm-linux-gnueabi target (i.e. no output). The bug does not trigger with -fsanitize=undefined but it does not show any output.