From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 12 Jan 2018 22:39:52 +0100 Subject: [Buildroot] [PATCH 1/2] toolchain: Fix the toolchain-wrapper to support more recent GCC versions In-Reply-To: <1515514108-18962-1-git-send-email-johannes.schmitz1@gmail.com> References: <1515514108-18962-1-git-send-email-johannes.schmitz1@gmail.com> Message-ID: <20180112223952.754b344d@windsurf.lan> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Tue, 9 Jan 2018 17:08:27 +0100, Johannes Schmitz wrote: > This fix is necessary for to build for MIPS, for example for the MIPS > XBurst architecture used on ci20 boards. > > Signed-off-by: Johannes Schmitz This is a bit short on explanation. Can you explain what it is fixing? Why is -mno-fused-madd no longer sufficient in recent gcc versions? The commit title is also not quite good, it doesn't mention that it's MIPS-related. Perhaps: toolchain: use -ffp-contract=off on MIPS XBust in the wrapper when needed > diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c > index 2928ea4..dd3a25e 100644 > --- a/toolchain/toolchain-wrapper.c > +++ b/toolchain/toolchain-wrapper.c > @@ -79,8 +79,14 @@ static char *predef_args[] = { > #ifdef BR_OMIT_LOCK_PREFIX > "-Wa,-momit-lock-prefix=yes", > #endif > -#ifdef BR_NO_FUSED_MADD > - "-mno-fused-madd", > +#ifdef BR2_TOOLCHAIN_GCC_AT_LEAST_4_6 This condition is not needed, because toolchain-wrapper.mk is already taking care of passing BR_NO_FUSED_MADD or BR2_FP_CONTRACT_OFF. > + #ifdef BR_FP_CONTRACT_OFF > + "-ffp-contract=off", > + #endif > +#else > + #ifdef BR_NO_FUSED_MADD > + "-mno-fused-madd", > + #endif > #endif > #ifdef BR_BINFMT_FLAT > "-Wl,-elf2flt", > diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk > index 7f72a0c..b7a4b9b 100644 > --- a/toolchain/toolchain-wrapper.mk > +++ b/toolchain/toolchain-wrapper.mk > @@ -28,7 +28,11 @@ endif > > # Avoid FPU bug on XBurst CPUs > ifeq ($(BR2_mips_xburst),y) > -TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD > + ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_6),y) > + TOOLCHAIN_WRAPPER_ARGS += -DBR_FP_CONTRACT_OFF > + else > + TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD > + endif Please don't indent lines. That's the Buildroot convention. Thanks, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com