From: Simon McVittie Date: Sun, 3 Oct 2021 23:32:24 +0100 Subject: build: Don't use SSE on i386 As of 2021, Debian's i386 baseline is still i686 minus one instruction, so it does not guarantee MMX or SSE. Forwarded: not-needed, Debian-specific --- Makefile | 5 ++++- ctf/Makefile | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 0a58fb5..a56c0bf 100644 --- a/Makefile +++ b/Makefile @@ -229,8 +229,11 @@ endif # -ffloat-store could work around that, but the better solution is to # just enforce SSE - every x86 CPU since Pentium3 supports that # and this should even improve the performance on old CPUs +# However, as of 2021, Debian's baseline for i386 is still officially a +# 20+ year old Geode, so we have to reduce performance on newer i386 CPUs +# to comply with that baseline. ifeq ($(YQ2_ARCH), i386) -override CFLAGS += -msse -mfpmath=sse +override CFLAGS += -ffloat-store endif # Force SSE math on x86_64. All sane compilers should do this diff --git a/ctf/Makefile b/ctf/Makefile index d616d6f..de47880 100755 --- a/ctf/Makefile +++ b/ctf/Makefile @@ -132,8 +132,11 @@ endif # -ffloat-store could work around that, but the better solution is to # just enforce SSE - every x86 CPU since Pentium3 supports that # and this should even improve the performance on old CPUs +# However, as of 2021, Debian's baseline for i386 is still officially a +# 20+ year old Geode, so we have to reduce performance on newer i386 CPUs +# to comply with that baseline. ifeq ($(YQ2_ARCH), i386) -override CFLAGS += -msse -mfpmath=sse +override CFLAGS += -ffloat-store endif # Force SSE math on x86_64. All sane compilers should do this