Re: [PATCH] tcg: Remove unused tcg_out_dupi_vec() stub

[Philippe Mathieu-Daudé]

Cc'ing Stefan.

On 1/10/21 5:10 AM, Wataru Ashihara wrote:
> This fixes the build with --enable-tcg-interpreter:
> 
>   clang -Ilibqemu-arm-softmmu.fa.p -I. -I.. -Itarget/arm -I../target/arm 
> -I../dtc/libfdt -I../capstone/include/capstone -Iqapi -Itrace -Iui 
> -Iui/shader -I/usr/include/pixman-1 -I/usr/include/glib-2.0 
> -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -Xclang -fcolor-diagnostics 
> -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -g -m64 -mcx16 -D_GNU_SOURCE 
> -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes 
> -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes 
> -fno-strict-aliasing -fno-common -fwrapv -Wold-style-definition -Wtype-limits 
> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body 
> -Wnested-externs -Wendif-labels -Wexpansion-to-defined 
> -Wno-initializer-overrides -Wno-missing-include-dirs 
> -Wno-shift-negative-value -Wno-string-plus-int -Wno-typedef-redefinition 
> -Wno-tautological-type-limit-compare -fstack-protector-strong -isystem 
> /home/wsh/qc/qemu/linux-headers -isystem linux-headers -iquote 
> /home/wsh/qc/qemu/tcg/tci -iquote . -iquote /home/wsh/qc/qemu -iquote 
> /home/wsh/qc/qemu/accel/tcg -iquote /home/wsh/qc/qemu/include -iquote 
> /home/wsh/qc/qemu/disas/libvixl -pthread -fPIC -isystem../linux-headers 
> -isystemlinux-headers -DNEED_CPU_H 
> '-DCONFIG_TARGET="arm-softmmu-config-target.h"' 
> '-DCONFIG_DEVICES="arm-softmmu-config-devices.h"' -MD -MQ 
> libqemu-arm-softmmu.fa.p/tcg_tcg.c.o -MF 
> libqemu-arm-softmmu.fa.p/tcg_tcg.c.o.d -o 
> libqemu-arm-softmmu.fa.p/tcg_tcg.c.o -c ../tcg/tcg.c
>   ../tcg/tcg.c:136:20: error: unused function 'tcg_out_dupi_vec' 
> [-Werror,-Wunused-function]
> 
> Signed-off-by: Wataru Ashihara <wataash@wataash.com>
> ---
>  tcg/tcg.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index 472bf1755b..32df149b12 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -117,8 +117,6 @@ static bool tcg_out_dup_vec(TCGContext *s, TCGType type, 
> unsigned vece,
>                              TCGReg dst, TCGReg src);
>  static bool tcg_out_dupm_vec(TCGContext *s, TCGType type, unsigned vece,
>                               TCGReg dst, TCGReg base, intptr_t offset);
> -static void tcg_out_dupi_vec(TCGContext *s, TCGType type,
> -                             TCGReg dst, tcg_target_long arg);
>  static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc, unsigned vecl,
>                             unsigned vece, const TCGArg *args,
>                             const int *const_args);
> @@ -133,11 +131,6 @@ static inline bool tcg_out_dupm_vec(TCGContext *s, 
> TCGType type, unsigned vece,
>  {
>      g_assert_not_reached();
>  }
> -static inline void tcg_out_dupi_vec(TCGContext *s, TCGType type,
> -                                    TCGReg dst, tcg_target_long arg)
> -{
> -    g_assert_not_reached();
> -}
>  static inline void tcg_out_vec_op(TCGContext *s, TCGOpcode opc, unsigned 
> vecl,
>                                    unsigned vece, const TCGArg *args,
>                                    const int *const_args)

AFAIK TCI does not support vectors, using them would trigger
tcg_debug_assert(type == TCG_TYPE_I64) in tcg_out_movi().

As your approach might break other backends, I'm going to
send an alternate patch using __attribute__((unused)).

Thanks for reporting this,

Phil.