On Mon, May 13, 2013 at 03:20:27PM +0200, Petar Jovanovic wrote:
> From: Petar Jovanovic <petar.jovano...@imgtec.com>
>
> This change makes sure that modifications of pos field in the DSPControl
> register do not trash other bits in the register. This bug can be triggered
> with the additional test case in mips32-dsp/extpdp.c in this commit.
>
> In addition to this, this change corrects incorrect calculation of the mask
> for EXTPDP.
>
> Signed-off-by: Petar Jovanovic <petar.jovano...@imgtec.com>
> ---
> target-mips/dsp_helper.c | 9 ++++-----
> tests/tcg/mips/mips32-dsp/extpdp.c | 18 ++++++++++++++++++
> 2 files changed, 22 insertions(+), 5 deletions(-)
>
> diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
> index a55f866..27283ed 100644
> --- a/target-mips/dsp_helper.c
> +++ b/target-mips/dsp_helper.c
> @@ -90,10 +90,10 @@ static inline void set_DSPControl_pos(uint32_t pos,
> CPUMIPSState *env)
> dspc = env->active_tc.DSPControl;
> #ifndef TARGET_MIPS64
> dspc = dspc & 0xFFFFFFC0;
> - dspc |= pos;
> + dspc |= (pos & 0x3F);
> #else
> dspc = dspc & 0xFFFFFF80;
> - dspc |= pos;
> + dspc |= (pos & 0x7F);
> #endif
> env->active_tc.DSPControl = dspc;
> }
> @@ -3439,10 +3439,9 @@ target_ulong helper_extpdp(target_ulong ac,
> target_ulong size,
> if (sub >= -1) {
> acc = ((uint64_t)env->active_tc.HI[ac] << 32) |
> ((uint64_t)env->active_tc.LO[ac] & MIPSDSP_LLO);
> - temp = (acc >> (start_pos - size)) &
> - (((uint32_t)0x01 << (size + 1)) - 1);
> + temp = (acc >> (start_pos - size)) & (~0U >> (31 - size));
>
> - set_DSPControl_pos(start_pos - (size + 1), env);
> + set_DSPControl_pos(sub & 0x3F, env);
I am not sure it is correct there for the 64-bit mode.
The value that should be written should be DSPcontrolpos6..0 - (size
+ 1), therefore keeeping only last 6 bits doesn't seems correct to me.
Given the change above, I think it should simply be
set_DSPControl_pos(sub, env);
> set_DSPControl_efi(0, env);
> } else {
> set_DSPControl_efi(1, env);
> diff --git a/tests/tcg/mips/mips32-dsp/extpdp.c
> b/tests/tcg/mips/mips32-dsp/extpdp.c
> index 15ba082..79ee16e 100644
> --- a/tests/tcg/mips/mips32-dsp/extpdp.c
> +++ b/tests/tcg/mips/mips32-dsp/extpdp.c
> @@ -42,5 +42,23 @@ int main()
> efi = (dsp >> 14) & 0x01;
> assert(efi == 1);
>
> +
> + ach = 0;
> + acl = 0;
> + dsp = 0;
> + result = 0;
> +
> + __asm
> + ("wrdsp %1\n\t"
> + "mthi %2, $ac1\n\t"
> + "mtlo %3, $ac1\n\t"
> + "extpdp %0, $ac1, 0x00\n\t"
> + "rddsp %1\n\t"
> + : "=r"(rt), "+r"(dsp)
> + : "r"(ach), "r"(acl)
> + );
> + assert(dsp == 0x3F);
> + assert(result == rt);
> +
> return 0;
> }
> --
> 1.7.9.5
>
>
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurel...@aurel32.net http://www.aurel32.net
