[kbuild-all] Re: [PATCH 2/2] selftests/fpu: Add an FPU selftest

On Sun, Jun 21, 2020 at 03:55:00AM +0800, kernel test robot wrote: > Hi Borislav, > > Thank you for the patch! Yet something to improve: > > [auto build test ERROR on kselftest/next] > [also build test ERROR on tip/auto-latest linus/master v5.8-rc1 next-20200618] > [cannot apply to tip/x86/core] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use as documented in > https://git-scm.com/docs/git-format-patch] > > url: https://github.com/0day-ci/linux/commits/Borislav-Petkov/x86-FPU-FPU-sani... > base: https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next > config: x86_64-allmodconfig (attached as .config) > compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 487ca07fcc75d52755c9fe2ee05bcb3b6eeeec44) > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # install x86_64 cross compiling tool for clang build > # apt-get install binutils-x86-64-linux-gnu > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp(a)intel.com&gt; > > All errors (new ones prefixed by >>, old ones prefixed by <<): > > >> ERROR: modpost: "__gtdf2" [lib/test_fpu.ko] undefined! > >> ERROR: modpost: "__divdf3" [lib/test_fpu.ko] undefined! > >> ERROR: modpost: "__muldf3" [lib/test_fpu.ko] undefined! > >> ERROR: modpost: "__adddf3" [lib/test_fpu.ko] undefined! Hmm, the point here is to actually have SSE* code in a kernel module for testing. And gcc does the right thing, see below. LLVM folks, how can I make llvm not call those library functions and actually spit out SSE* code? Full build command is: /mnt/smr/share/src/llvm/tc-build/install/bin/clang-11 -Wp,-MMD,lib/.test_fpu.o.d -nostdinc -isystem /mnt/smr/share/src/llvm/tc-build/install/lib/clang/11.0.0/include -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -Qunused-arguments -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Wno-format-security -std=gnu89 -no-integrated-as -Werror=unknown-warning-option -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -m64 -mno-80387 -mstack-alignment=8 -march=k8 -mno-red-zone -mcmodel=kernel -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -fno-delete-null-pointer-checks -Wno-frame-address -Wno-address-of-packed-member -O2 -Wframe-larger-than=2048 -fstack-protector -Wno-format-invalid-specifier -Wno-gnu -mno-global-merge -Wno-unused-const-variable -g -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -fno-strict-overflow -fno-merge-all-constants -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -fmacro-prefix-map=./= -fcf-protection=none -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -mhard-float -msse -DMODULE -DKBUILD_BASENAME='"test_fpu"' -DKBUILD_MODNAME='"test_fpu"' -c -o lib/test_fpu.o lib/test_fpu.c

Thx. --- /tmp/test_fpu.s.gcc 2020-06-22 18:51:25.828615337 +0200 +++ /tmp/test_fpu.s.llvm-11 2020-06-22 18:50:35.080614534 +0200 @@ -1,74 +1,49 @@ -test_fpu_get: - pushq %r12 # - pushq %rbx # - movq %rsi, %rbx # tmp119, val - subq $56, %rsp #, -# lib/test_fpu.c:58: kernel_fpu_begin(); - call kernel_fpu_begin # -# lib/test_fpu.c:32: a = 4.0; - movlpd .LC1(%rip), %xmm0 #, tmp106 - movsd %xmm0, (%rsp) # tmp106, a -# lib/test_fpu.c:33: b = 1e-15; - movlpd .LC2(%rip), %xmm0 #, tmp107 - movsd %xmm0, 8(%rsp) # tmp107, b -# lib/test_fpu.c:34: c = 1e-310; - movlpd .LC3(%rip), %xmm0 #, tmp108 - movsd %xmm0, 16(%rsp) # tmp108, c -# lib/test_fpu.c:37: d = a + b; - movlpd (%rsp), %xmm0 # a, a.2_8 - movlpd 8(%rsp), %xmm1 # b, b.3_9 - addsd %xmm1, %xmm0 # b.3_9, _10 -# lib/test_fpu.c:37: d = a + b; - movsd %xmm0, 24(%rsp) # _10, d -# lib/test_fpu.c:40: e = a + b / 2; - movlpd 8(%rsp), %xmm0 # b, b.4_11 -# lib/test_fpu.c:40: e = a + b / 2; - movlpd (%rsp), %xmm1 # a, a.5_13 -# lib/test_fpu.c:40: e = a + b / 2; - mulsd .LC4(%rip), %xmm0 #, tmp109 -# lib/test_fpu.c:40: e = a + b / 2; - addsd %xmm1, %xmm0 # a.5_13, _14 -# lib/test_fpu.c:40: e = a + b / 2; - movsd %xmm0, 32(%rsp) # _14, e -# lib/test_fpu.c:43: f = b / c; - movlpd 8(%rsp), %xmm0 # b, b.6_15 - movlpd 16(%rsp), %xmm1 # c, c.7_16 - divsd %xmm1, %xmm0 # c.7_16, _17 -# lib/test_fpu.c:43: f = b / c; - movsd %xmm0, 40(%rsp) # _17, f -# lib/test_fpu.c:46: g = a + c * f; - movlpd 16(%rsp), %xmm0 # c, c.8_18 - movlpd 40(%rsp), %xmm2 # f, f.9_19 -# lib/test_fpu.c:46: g = a + c * f; - movlpd (%rsp), %xmm1 # a, a.10_21 -# lib/test_fpu.c:46: g = a + c * f; - mulsd %xmm2, %xmm0 # f.9_19, tmp111 -# lib/test_fpu.c:46: g = a + c * f; - addsd %xmm1, %xmm0 # a.10_21, _22 -# lib/test_fpu.c:46: g = a + c * f; - movsd %xmm0, 48(%rsp) # _22, g -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - movlpd 24(%rsp), %xmm1 # d, d.11_23 - movlpd (%rsp), %xmm0 # a, a.12_24 -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - comisd %xmm0, %xmm1 # a.12_24, d.11_23 - jbe .L15 #, -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - movlpd 32(%rsp), %xmm1 # e, e.13_25 - movlpd (%rsp), %xmm0 # a, a.14_26 -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - comisd %xmm0, %xmm1 # a.14_26, e.13_25 - jbe .L15 #, -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - movlpd 48(%rsp), %xmm1 # g, g.15_27 -# lib/test_fpu.c:51: return -EINVAL; - movl $0, %r12d #, tmp117 - movl $-22, %eax #, tmp118 -# lib/test_fpu.c:48: if (d > a && e > a && g > a) - movlpd (%rsp), %xmm0 # a, a.16_28 -# lib/test_fpu.c:51: return -EINVAL; - comisd %xmm0, %xmm1 # a.16_28, g.15_27 - cmovbe %eax, %r12d # tmp117,, tmp118, <retval> -.L4: -# lib/test_fpu.c:60: kernel_fpu_end(); - call kernel_fpu_end # +test_fpu_get: # @test_fpu_get +# %bb.0: + pushq %rbp + pushq %rbx + subq $56, %rsp + movq %rsi, %rbx + callq kernel_fpu_begin + movabsq $4616189618054758400, %rax # imm = 0x4010000000000000 + movq %rax, (%rsp) + movabsq $4382569440205035030, %rax # imm = 0x3CD203AF9EE75616 + movq %rax, 8(%rsp) + movabsq $20240225330731, %rax # imm = 0x12688B70E62B + movq %rax, 16(%rsp) + movq (%rsp), %rdi + movq 8(%rsp), %rsi + callq __adddf3 + movq %rax, 48(%rsp) + movq (%rsp), %rbp + movq 8(%rsp), %rdi + movabsq $4602678819172646912, %rsi # imm = 0x3FE0000000000000 + callq __muldf3 + movq %rbp, %rdi + movq %rax, %rsi + callq __adddf3 + movq %rax, 40(%rsp) + movq 8(%rsp), %rdi + movq 16(%rsp), %rsi + callq __divdf3 + movq %rax, 32(%rsp) + movq (%rsp), %rbp + movq 16(%rsp), %rdi + movq 32(%rsp), %rsi + callq __muldf3 + movq %rbp, %rdi + movq %rax, %rsi + callq __adddf3 + movq %rax, 24(%rsp) + movq 48(%rsp), %rdi + movq (%rsp), %rsi + callq __gtdf2 + testl %eax, %eax + jle .LBB3_3 +# %bb.1: + movq 40(%rsp), %rdi + movq (%rsp), %rsi + callq __gtdf2 + testl %eax, %eax + jle .LBB3_3 +# %bb.2: -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette -- You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe(a)googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200622170446.GG3220....