LGTM.
Kito Cheng <k...@andestech.com> 於 2019年3月26日 週二 下午1:29寫道：
> From: Kito Cheng <kito.ch...@gmail.com>
>
> Kito Cheng <kito.ch...@gmail.com>
> Shiva Chen <shiva0...@gmail.com>
>
> ChangeLog:
> gcc/
> * config/nds32/nds32-md-auxiliary.c (nds32_split_ashiftdi3):
> Fix wrong code gen with large shift amount.
>
> gcc/testsuite/
> * gcc.target/nds32/ashiftdi3.c: New.
> ---
> gcc/config/nds32/nds32-md-auxiliary.c | 21 ++++++++++++++-------
> gcc/testsuite/gcc.target/nds32/ashiftdi3.c | 23 +++++++++++++++++++++++
> 2 files changed, 37 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/nds32/ashiftdi3.c
>
> diff --git a/gcc/config/nds32/nds32-md-auxiliary.c
> b/gcc/config/nds32/nds32-md-auxiliary.c
> index 35fcc64..eadd841 100644
> --- a/gcc/config/nds32/nds32-md-auxiliary.c
> +++ b/gcc/config/nds32/nds32-md-auxiliary.c
> @@ -3304,15 +3304,22 @@ nds32_split_ashiftdi3 (rtx dst, rtx src, rtx
> shiftamount)
> ext_start = gen_reg_rtx (SImode);
>
> /*
> - if (shiftamount < 32)
> + # In fact, we want to check shift amonut is great than or equal
> 32,
> + # but in some corner case, the shift amount might be very large
> value,
> + # however we've defined SHIFT_COUNT_TRUNCATED, so GCC think we've
> + # handle that correctly without any truncate.
> + # so check the the condition of (shiftamount & 32) is most
> + # safe way to do.
> + if (shiftamount & 32)
> + dst_low_part = 0
> + dst_high_part = src_low_part << shiftamount & 0x1f
> + else
> dst_low_part = src_low_part << shiftamout
> dst_high_part = wext (src, 32 - shiftamount)
> # wext can't handle wext (src, 32) since it's only take rb[0:4]
> # for extract.
> dst_high_part = shiftamount == 0 ? src_high_part : dst_high_part
> - else
> - dst_low_part = 0
> - dst_high_part = src_low_part << shiftamount & 0x1f
> +
> */
>
> emit_insn (gen_subsi3 (ext_start,
> @@ -3331,11 +3338,11 @@ nds32_split_ashiftdi3 (rtx dst, rtx src, rtx
> shiftamount)
> emit_insn (gen_ashlsi3 (dst_high_part_g32, src_low_part,
> new_shift_amout));
>
> - emit_insn (gen_slt_compare (select_reg, shiftamount, GEN_INT (32)));
> + emit_insn (gen_andsi3 (select_reg, shiftamount, GEN_INT (32)));
>
> - emit_insn (gen_cmovnsi (dst_low_part, select_reg,
> + emit_insn (gen_cmovzsi (dst_low_part, select_reg,
> dst_low_part_l32, dst_low_part_g32));
> - emit_insn (gen_cmovnsi (dst_high_part, select_reg,
> + emit_insn (gen_cmovzsi (dst_high_part, select_reg,
> dst_high_part_l32, dst_high_part_g32));
> }
> }
> diff --git a/gcc/testsuite/gcc.target/nds32/ashiftdi3.c
> b/gcc/testsuite/gcc.target/nds32/ashiftdi3.c
> new file mode 100644
> index 0000000..e3faff5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/nds32/ashiftdi3.c
> @@ -0,0 +1,23 @@
> +/* { dg-options "-mext-dsp" { target nds32 } } */
> +
> +#include<stdio.h>
> +extern void abort (void);
> +
> +unsigned long long int ull;
> +
> +unsigned long long int __attribute__ ((noinline))
> +foo (unsigned long long int a, unsigned long long int b)
> +{
> + return a << b;
> +}
> +
> +int
> +main (void)
> +{
> + unsigned long long shiftamt = 0x45806aca;
> + ull = foo(0xfffffffff, shiftamt);
> + if (ull != 70368744176640)
> + abort ();
> +
> + return 0;
> +}
> --
> 1.8.3.1
>
>
