Re: [PATCH v2] Remove Intel compiler support

From: Nathan Chancellor
Date: Thu Oct 13 2022 - 16:02:48 EST


On Wed, Oct 12, 2022 at 02:14:27AM +0900, Masahiro Yamada wrote:
> include/linux/compiler-intel.h had no update in the past 3 years.
>
> We often forget about the third C compiler to build the kernel.
> For example, commit a0a12c3ed057 ("asm goto: eradicate CC_HAS_ASM_GOTO")
> only mentioned GCC and Clang.
>
> init/Kconfig defines CC_IS_GCC and CC_IS_CLANG but not CC_IS_ICC,
> and nobody has reported any issue.
>
> I guess the Intel Compiler support is broken, and nobody is caring
> about it.
>
> Harald Arnesen pointed out ICC (classic Intel C/C++ compiler) is
> deprecated:
>
> $ icc -v
> icc: remark #10441: The Intel(R) C++ Compiler Classic (ICC) is
> deprecated and will be removed from product release in the second half
> of 2023. The Intel(R) oneAPI DPC++/C++ Compiler (ICX) is the recommended
> compiler moving forward. Please transition to use this compiler. Use
> '-diag-disable=10441' to disable this message.
> icc version 2021.7.0 (gcc version 12.1.0 compatibility)
>
> Arnd Bergmann provided a link to the article, "Intel C/C++ compilers
> complete adoption of LLVM".
>
> Link: https://www.intel.com/content/www/us/en/developer/articles/technical/adoption-of-llvm-complete-icx.html
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>

> ---
>
> Changes in v2:
> - Remove "not supported by icc." comments from compiler_attributes.h
> - Clean up __assume_aligned() macro
> - Add more info from Harald Arnesen and Arnd Bergmann
>
> arch/ia64/include/uapi/asm/cmpxchg.h | 6 +-
> arch/ia64/include/uapi/asm/intel_intrin.h | 162 ----------------------
> arch/ia64/include/uapi/asm/intrinsics.h | 6 +-
> include/acpi/platform/acenv.h | 5 +-
> include/acpi/platform/acenvex.h | 2 +-
> include/acpi/platform/acintel.h | 55 --------
> include/linux/compiler-intel.h | 34 -----
> include/linux/compiler_attributes.h | 14 +-
> include/linux/compiler_types.h | 2 -
> lib/zstd/common/compiler.h | 2 +-
> lib/zstd/compress/zstd_fast.c | 7 -
> scripts/cc-version.sh | 2 -
> scripts/min-tool-version.sh | 4 -
> 13 files changed, 6 insertions(+), 295 deletions(-)
> delete mode 100644 arch/ia64/include/uapi/asm/intel_intrin.h
> delete mode 100644 include/acpi/platform/acintel.h
> delete mode 100644 include/linux/compiler-intel.h
>
> diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h
> index ca2e02685343..259ae57570bf 100644
> --- a/arch/ia64/include/uapi/asm/cmpxchg.h
> +++ b/arch/ia64/include/uapi/asm/cmpxchg.h
> @@ -15,11 +15,7 @@
> #include <linux/types.h>
> /* include compiler specific intrinsics */
> #include <asm/ia64regs.h>
> -#ifdef __INTEL_COMPILER
> -# include <asm/intel_intrin.h>
> -#else
> -# include <asm/gcc_intrin.h>
> -#endif
> +#include <asm/gcc_intrin.h>
>
> /*
> * This function doesn't exist, so you'll get a linker error if
> diff --git a/arch/ia64/include/uapi/asm/intel_intrin.h b/arch/ia64/include/uapi/asm/intel_intrin.h
> deleted file mode 100644
> index dc1884dc54b5..000000000000
> --- a/arch/ia64/include/uapi/asm/intel_intrin.h
> +++ /dev/null
> @@ -1,162 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> -#ifndef _ASM_IA64_INTEL_INTRIN_H
> -#define _ASM_IA64_INTEL_INTRIN_H
> -/*
> - * Intel Compiler Intrinsics
> - *
> - * Copyright (C) 2002,2003 Jun Nakajima <jun.nakajima@xxxxxxxxx>
> - * Copyright (C) 2002,2003 Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
> - * Copyright (C) 2005,2006 Hongjiu Lu <hongjiu.lu@xxxxxxxxx>
> - *
> - */
> -#include <ia64intrin.h>
> -
> -#define ia64_barrier() __memory_barrier()
> -
> -#define ia64_stop() /* Nothing: As of now stop bit is generated for each
> - * intrinsic
> - */
> -
> -#define ia64_getreg __getReg
> -#define ia64_setreg __setReg
> -
> -#define ia64_hint __hint
> -#define ia64_hint_pause __hint_pause
> -
> -#define ia64_mux1_brcst _m64_mux1_brcst
> -#define ia64_mux1_mix _m64_mux1_mix
> -#define ia64_mux1_shuf _m64_mux1_shuf
> -#define ia64_mux1_alt _m64_mux1_alt
> -#define ia64_mux1_rev _m64_mux1_rev
> -
> -#define ia64_mux1(x,v) _m_to_int64(_m64_mux1(_m_from_int64(x), (v)))
> -#define ia64_popcnt _m64_popcnt
> -#define ia64_getf_exp __getf_exp
> -#define ia64_shrp _m64_shrp
> -
> -#define ia64_tpa __tpa
> -#define ia64_invala __invala
> -#define ia64_invala_gr __invala_gr
> -#define ia64_invala_fr __invala_fr
> -#define ia64_nop __nop
> -#define ia64_sum __sum
> -#define ia64_ssm __ssm
> -#define ia64_rum __rum
> -#define ia64_rsm __rsm
> -#define ia64_fc __fc
> -
> -#define ia64_ldfs __ldfs
> -#define ia64_ldfd __ldfd
> -#define ia64_ldfe __ldfe
> -#define ia64_ldf8 __ldf8
> -#define ia64_ldf_fill __ldf_fill
> -
> -#define ia64_stfs __stfs
> -#define ia64_stfd __stfd
> -#define ia64_stfe __stfe
> -#define ia64_stf8 __stf8
> -#define ia64_stf_spill __stf_spill
> -
> -#define ia64_mf __mf
> -#define ia64_mfa __mfa
> -
> -#define ia64_fetchadd4_acq __fetchadd4_acq
> -#define ia64_fetchadd4_rel __fetchadd4_rel
> -#define ia64_fetchadd8_acq __fetchadd8_acq
> -#define ia64_fetchadd8_rel __fetchadd8_rel
> -
> -#define ia64_xchg1 _InterlockedExchange8
> -#define ia64_xchg2 _InterlockedExchange16
> -#define ia64_xchg4 _InterlockedExchange
> -#define ia64_xchg8 _InterlockedExchange64
> -
> -#define ia64_cmpxchg1_rel _InterlockedCompareExchange8_rel
> -#define ia64_cmpxchg1_acq _InterlockedCompareExchange8_acq
> -#define ia64_cmpxchg2_rel _InterlockedCompareExchange16_rel
> -#define ia64_cmpxchg2_acq _InterlockedCompareExchange16_acq
> -#define ia64_cmpxchg4_rel _InterlockedCompareExchange_rel
> -#define ia64_cmpxchg4_acq _InterlockedCompareExchange_acq
> -#define ia64_cmpxchg8_rel _InterlockedCompareExchange64_rel
> -#define ia64_cmpxchg8_acq _InterlockedCompareExchange64_acq
> -
> -#define __ia64_set_dbr(index, val) \
> - __setIndReg(_IA64_REG_INDR_DBR, index, val)
> -#define ia64_set_ibr(index, val) \
> - __setIndReg(_IA64_REG_INDR_IBR, index, val)
> -#define ia64_set_pkr(index, val) \
> - __setIndReg(_IA64_REG_INDR_PKR, index, val)
> -#define ia64_set_pmc(index, val) \
> - __setIndReg(_IA64_REG_INDR_PMC, index, val)
> -#define ia64_set_pmd(index, val) \
> - __setIndReg(_IA64_REG_INDR_PMD, index, val)
> -#define ia64_set_rr(index, val) \
> - __setIndReg(_IA64_REG_INDR_RR, index, val)
> -
> -#define ia64_get_cpuid(index) \
> - __getIndReg(_IA64_REG_INDR_CPUID, index)
> -#define __ia64_get_dbr(index) __getIndReg(_IA64_REG_INDR_DBR, index)
> -#define ia64_get_ibr(index) __getIndReg(_IA64_REG_INDR_IBR, index)
> -#define ia64_get_pkr(index) __getIndReg(_IA64_REG_INDR_PKR, index)
> -#define ia64_get_pmc(index) __getIndReg(_IA64_REG_INDR_PMC, index)
> -#define ia64_get_pmd(index) __getIndReg(_IA64_REG_INDR_PMD, index)
> -#define ia64_get_rr(index) __getIndReg(_IA64_REG_INDR_RR, index)
> -
> -#define ia64_srlz_d __dsrlz
> -#define ia64_srlz_i __isrlz
> -
> -#define ia64_dv_serialize_data()
> -#define ia64_dv_serialize_instruction()
> -
> -#define ia64_st1_rel __st1_rel
> -#define ia64_st2_rel __st2_rel
> -#define ia64_st4_rel __st4_rel
> -#define ia64_st8_rel __st8_rel
> -
> -/* FIXME: need st4.rel.nta intrinsic */
> -#define ia64_st4_rel_nta __st4_rel
> -
> -#define ia64_ld1_acq __ld1_acq
> -#define ia64_ld2_acq __ld2_acq
> -#define ia64_ld4_acq __ld4_acq
> -#define ia64_ld8_acq __ld8_acq
> -
> -#define ia64_sync_i __synci
> -#define ia64_thash __thash
> -#define ia64_ttag __ttag
> -#define ia64_itcd __itcd
> -#define ia64_itci __itci
> -#define ia64_itrd __itrd
> -#define ia64_itri __itri
> -#define ia64_ptce __ptce
> -#define ia64_ptcl __ptcl
> -#define ia64_ptcg __ptcg
> -#define ia64_ptcga __ptcga
> -#define ia64_ptri __ptri
> -#define ia64_ptrd __ptrd
> -#define ia64_dep_mi _m64_dep_mi
> -
> -/* Values for lfhint in __lfetch and __lfetch_fault */
> -
> -#define ia64_lfhint_none __lfhint_none
> -#define ia64_lfhint_nt1 __lfhint_nt1
> -#define ia64_lfhint_nt2 __lfhint_nt2
> -#define ia64_lfhint_nta __lfhint_nta
> -
> -#define ia64_lfetch __lfetch
> -#define ia64_lfetch_excl __lfetch_excl
> -#define ia64_lfetch_fault __lfetch_fault
> -#define ia64_lfetch_fault_excl __lfetch_fault_excl
> -
> -#define ia64_intrin_local_irq_restore(x) \
> -do { \
> - if ((x) != 0) { \
> - ia64_ssm(IA64_PSR_I); \
> - ia64_srlz_d(); \
> - } else { \
> - ia64_rsm(IA64_PSR_I); \
> - } \
> -} while (0)
> -
> -#define __builtin_trap() __break(0);
> -
> -#endif /* _ASM_IA64_INTEL_INTRIN_H */
> diff --git a/arch/ia64/include/uapi/asm/intrinsics.h b/arch/ia64/include/uapi/asm/intrinsics.h
> index a0e0a064f5b1..63f27c4ec739 100644
> --- a/arch/ia64/include/uapi/asm/intrinsics.h
> +++ b/arch/ia64/include/uapi/asm/intrinsics.h
> @@ -14,11 +14,7 @@
> #include <linux/types.h>
> /* include compiler specific intrinsics */
> #include <asm/ia64regs.h>
> -#ifdef __INTEL_COMPILER
> -# include <asm/intel_intrin.h>
> -#else
> -# include <asm/gcc_intrin.h>
> -#endif
> +#include <asm/gcc_intrin.h>
> #include <asm/cmpxchg.h>
>
> #define ia64_set_rr0_to_rr4(val0, val1, val2, val3, val4) \
> diff --git a/include/acpi/platform/acenv.h b/include/acpi/platform/acenv.h
> index 03eb3d977075..9e4f7564201a 100644
> --- a/include/acpi/platform/acenv.h
> +++ b/include/acpi/platform/acenv.h
> @@ -148,15 +148,12 @@
> *
> *****************************************************************************/
>
> -#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
> +#if defined(__GNUC__)
> #include <acpi/platform/acgcc.h>
>
> #elif defined(_MSC_VER)
> #include "acmsvc.h"
>
> -#elif defined(__INTEL_COMPILER)
> -#include <acpi/platform/acintel.h>
> -
> #endif
>
> #if defined(_LINUX) || defined(__linux__)
> diff --git a/include/acpi/platform/acenvex.h b/include/acpi/platform/acenvex.h
> index 3a6b1db9a984..72cc7bab469e 100644
> --- a/include/acpi/platform/acenvex.h
> +++ b/include/acpi/platform/acenvex.h
> @@ -35,7 +35,7 @@
>
> #endif
>
> -#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
> +#if defined(__GNUC__)
> #include "acgccex.h"
>
> #elif defined(_MSC_VER)
> diff --git a/include/acpi/platform/acintel.h b/include/acpi/platform/acintel.h
> deleted file mode 100644
> index 85b1ae86ee63..000000000000
> --- a/include/acpi/platform/acintel.h
> +++ /dev/null
> @@ -1,55 +0,0 @@
> -/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
> -/******************************************************************************
> - *
> - * Name: acintel.h - VC specific defines, etc.
> - *
> - * Copyright (C) 2000 - 2022, Intel Corp.
> - *
> - *****************************************************************************/
> -
> -#ifndef __ACINTEL_H__
> -#define __ACINTEL_H__
> -
> -/*
> - * Use compiler specific <stdarg.h> is a good practice for even when
> - * -nostdinc is specified (i.e., ACPI_USE_STANDARD_HEADERS undefined.
> - */
> -#ifndef va_arg
> -#include <stdarg.h>
> -#endif
> -
> -/* Configuration specific to Intel 64-bit C compiler */
> -
> -#define COMPILER_DEPENDENT_INT64 __int64
> -#define COMPILER_DEPENDENT_UINT64 unsigned __int64
> -#define ACPI_INLINE __inline
> -
> -/*
> - * Calling conventions:
> - *
> - * ACPI_SYSTEM_XFACE - Interfaces to host OS (handlers, threads)
> - * ACPI_EXTERNAL_XFACE - External ACPI interfaces
> - * ACPI_INTERNAL_XFACE - Internal ACPI interfaces
> - * ACPI_INTERNAL_VAR_XFACE - Internal variable-parameter list interfaces
> - */
> -#define ACPI_SYSTEM_XFACE
> -#define ACPI_EXTERNAL_XFACE
> -#define ACPI_INTERNAL_XFACE
> -#define ACPI_INTERNAL_VAR_XFACE
> -
> -/* remark 981 - operands evaluated in no particular order */
> -#pragma warning(disable:981)
> -
> -/* warn C4100: unreferenced formal parameter */
> -#pragma warning(disable:4100)
> -
> -/* warn C4127: conditional expression is constant */
> -#pragma warning(disable:4127)
> -
> -/* warn C4706: assignment within conditional expression */
> -#pragma warning(disable:4706)
> -
> -/* warn C4214: bit field types other than int */
> -#pragma warning(disable:4214)
> -
> -#endif /* __ACINTEL_H__ */
> diff --git a/include/linux/compiler-intel.h b/include/linux/compiler-intel.h
> deleted file mode 100644
> index b17f3cd18334..000000000000
> --- a/include/linux/compiler-intel.h
> +++ /dev/null
> @@ -1,34 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef __LINUX_COMPILER_TYPES_H
> -#error "Please don't include <linux/compiler-intel.h> directly, include <linux/compiler.h> instead."
> -#endif
> -
> -#ifdef __ECC
> -
> -/* Compiler specific definitions for Intel ECC compiler */
> -
> -#include <asm/intrinsics.h>
> -
> -/* Intel ECC compiler doesn't support gcc specific asm stmts.
> - * It uses intrinsics to do the equivalent things.
> - */
> -
> -#define barrier() __memory_barrier()
> -#define barrier_data(ptr) barrier()
> -
> -#define RELOC_HIDE(ptr, off) \
> - ({ unsigned long __ptr; \
> - __ptr = (unsigned long) (ptr); \
> - (typeof(ptr)) (__ptr + (off)); })
> -
> -/* This should act as an optimization barrier on var.
> - * Given that this compiler does not have inline assembly, a compiler barrier
> - * is the best we can do.
> - */
> -#define OPTIMIZER_HIDE_VAR(var) barrier()
> -
> -#endif
> -
> -/* icc has this, but it's called _bswap16 */
> -#define __HAVE_BUILTIN_BSWAP16__
> -#define __builtin_bswap16 _bswap16
> diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
> index 898b3458b24a..9221302f6ae8 100644
> --- a/include/linux/compiler_attributes.h
> +++ b/include/linux/compiler_attributes.h
> @@ -64,16 +64,10 @@
> * compiler should see some alignment anyway, when the return value is
> * massaged by 'flags = ptr & 3; ptr &= ~3;').
> *
> - * Optional: not supported by icc
> - *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-assume_005faligned-function-attribute
> * clang: https://clang.llvm.org/docs/AttributeReference.html#assume-aligned
> */
> -#if __has_attribute(__assume_aligned__)
> -# define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
> -#else
> -# define __assume_aligned(a, ...)
> -#endif
> +#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
>
> /*
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute
> @@ -91,7 +85,6 @@
> /*
> * Optional: only supported since gcc >= 9
> * Optional: not supported by clang
> - * Optional: not supported by icc
> *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-copy-function-attribute
> */
> @@ -104,7 +97,6 @@
> /*
> * Optional: not supported by gcc
> * Optional: only supported since clang >= 14.0
> - * Optional: not supported by icc
> *
> * clang: https://clang.llvm.org/docs/AttributeReference.html#diagnose_as_builtin
> */
> @@ -128,7 +120,6 @@
>
> /*
> * Optional: not supported by clang
> - * Optional: not supported by icc
> *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-designated_005finit-type-attribute
> */
> @@ -242,7 +233,6 @@
> /*
> * Optional: only supported since gcc >= 8
> * Optional: not supported by clang
> - * Optional: not supported by icc
> *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute
> */
> @@ -273,7 +263,6 @@
>
> /*
> * Optional: not supported by gcc.
> - * Optional: not supported by icc.
> *
> * clang: https://clang.llvm.org/docs/AttributeReference.html#overloadable
> */
> @@ -293,7 +282,6 @@
> * Note: the "type" argument should match any __builtin_object_size(p, type) usage.
> *
> * Optional: not supported by gcc.
> - * Optional: not supported by icc.
> *
> * clang: https://clang.llvm.org/docs/AttributeReference.html#pass-object-size-pass-dynamic-object-size
> */
> diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> index 74e04ecd4c89..0e06a1a79401 100644
> --- a/include/linux/compiler_types.h
> +++ b/include/linux/compiler_types.h
> @@ -92,8 +92,6 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
> /* Compiler specific macros. */
> #ifdef __clang__
> #include <linux/compiler-clang.h>
> -#elif defined(__INTEL_COMPILER)
> -#include <linux/compiler-intel.h>
> #elif defined(__GNUC__)
> /* The above compilers also define __GNUC__, so order is important here. */
> #include <linux/compiler-gcc.h>
> diff --git a/lib/zstd/common/compiler.h b/lib/zstd/common/compiler.h
> index f5a9c70a228a..c281a6430cd4 100644
> --- a/lib/zstd/common/compiler.h
> +++ b/lib/zstd/common/compiler.h
> @@ -116,7 +116,7 @@
>
> /* vectorization
> * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax */
> -#if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__)
> +#if !defined(__clang__) && defined(__GNUC__)
> # if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5)
> # define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
> # else
> diff --git a/lib/zstd/compress/zstd_fast.c b/lib/zstd/compress/zstd_fast.c
> index 96b7d48e2868..800f3865119f 100644
> --- a/lib/zstd/compress/zstd_fast.c
> +++ b/lib/zstd/compress/zstd_fast.c
> @@ -80,13 +80,6 @@ ZSTD_compressBlock_fast_generic(
> }
>
> /* Main Search Loop */
> -#ifdef __INTEL_COMPILER
> - /* From intel 'The vector pragma indicates that the loop should be
> - * vectorized if it is legal to do so'. Can be used together with
> - * #pragma ivdep (but have opted to exclude that because intel
> - * warns against using it).*/
> - #pragma vector always
> -#endif
> while (ip1 < ilimit) { /* < instead of <=, because check at ip0+2 */
> size_t mLength;
> BYTE const* ip2 = ip0 + 2;
> diff --git a/scripts/cc-version.sh b/scripts/cc-version.sh
> index 2401c86fcf53..0573c92e841d 100755
> --- a/scripts/cc-version.sh
> +++ b/scripts/cc-version.sh
> @@ -12,8 +12,6 @@ get_c_compiler_info()
> cat <<- EOF | "$@" -E -P -x c - 2>/dev/null
> #if defined(__clang__)
> Clang __clang_major__ __clang_minor__ __clang_patchlevel__
> - #elif defined(__INTEL_COMPILER)
> - ICC __INTEL_COMPILER __INTEL_COMPILER_UPDATE
> #elif defined(__GNUC__)
> GCC __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__
> #else
> diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> index b6593eac5003..8766e248ffbb 100755
> --- a/scripts/min-tool-version.sh
> +++ b/scripts/min-tool-version.sh
> @@ -19,10 +19,6 @@ binutils)
> gcc)
> echo 5.1.0
> ;;
> -icc)
> - # temporary
> - echo 16.0.3
> - ;;
> llvm)
> if [ "$SRCARCH" = s390 ]; then
> echo 14.0.0
> --
> 2.34.1
>