Hi Simon,
On Thu, Sep 28, 2023 at 10:20 PM Simon Glass sjg@chromium.org wrote:
Hi Bin,
On Thu, 28 Sept 2023 at 08:15, Bin Meng bmeng.cn@gmail.com wrote:
Hi Simon,
On Thu, Sep 28, 2023 at 10:41 AM Simon Glass sjg@chromium.org wrote:
Hi Bin,
U-Boot 64-bit on x86 disables sse, but when enabling Truetype I get a compiler error:
drivers/video/console_truetype.c: In function 'frac': drivers/video/console_truetype.c:30:15: error: SSE register return with SSE disabled 30 | static double frac(double val)
Do you know how to enable SSE for 64-bit?
The following patch could enable SSE for 64-bit:
diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 26ec1af2f0..250d7c9948 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -27,7 +27,7 @@ ifeq ($(IS_32BIT),y) PLATFORM_CPPFLAGS += -march=i386 -m32 else PLATFORM_CPPFLAGS += $(if $(CONFIG_SPL_BUILD),,-fpic) -fno-common -march=core2 -m64 -PLATFORM_CPPFLAGS += -mno-mmx -mno-sse +PLATFORM_CPPFLAGS += -mno-mmx endif
However as Heinrich mentioned, U-Boot codes should be written in a "floating point free" way.
The fix should really be updating console_truetype.c to use integers instead of using float/double.
Yes, I can do that, but it hangs going into 64-bit mode, which is presumably why the flag was added. In fact it was your commit!
Yeah, indeed it was commit dd4611dea435 ("x86: Ensure no instruction sets of MMX/SSE are generated in 64-bit build") and the commit message said the reason.
Is there some missing init somewhere?
I believe we should turn on X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT on CR4 to enable SSE.
Regards, Bin