[Qemu-devel] [PATCH 0/3] muldiv64() trivial fixes

[Qemu-devel] [PATCH 0/3] muldiv64() trivial fixes

[Laurent Vivier]

Some fixes in the use of muldiv64()

The patches have been generated with the help of coccinelle.

The first patch contains the scripts used to generate the two following
patches. As it is done for linux, I've added the scripts under
scripts/coccinelle.

Laurent Vivier (3):
  scripts: add muldiv64() checking coccinelle scripts
  The only 64bit parameter of muldiv64() is the first one.
  remove useless muldiv64()

 hw/timer/omap_gptimer.c                  |  4 +--
 hw/usb/hcd-ohci.c                        |  2 +-
 scripts/coccinelle/remove_muldiv64.cocci |  6 +++++
 scripts/coccinelle/swap_muldiv64.cocci   | 46 ++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 3 deletions(-)
 create mode 100644 scripts/coccinelle/remove_muldiv64.cocci
 create mode 100644 scripts/coccinelle/swap_muldiv64.cocci

-- 
2.5.5

[Qemu-devel] [PATCH 1/3] scripts: add muldiv64() checking coccinelle scripts

[Laurent Vivier]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 scripts/coccinelle/remove_muldiv64.cocci |  6 +++++
 scripts/coccinelle/swap_muldiv64.cocci   | 46 ++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 scripts/coccinelle/remove_muldiv64.cocci
 create mode 100644 scripts/coccinelle/swap_muldiv64.cocci

diff --git a/scripts/coccinelle/remove_muldiv64.cocci b/scripts/coccinelle/remove_muldiv64.cocci
new file mode 100644
index 0000000..4c10bd5
--- /dev/null
+++ b/scripts/coccinelle/remove_muldiv64.cocci
@@ -0,0 +1,6 @@
+// replace muldiv64(a, 1, b) by "a / b"
+@@
+expression a, b;
+@@
+-muldiv64(a, 1, b)
++a / b
diff --git a/scripts/coccinelle/swap_muldiv64.cocci b/scripts/coccinelle/swap_muldiv64.cocci
new file mode 100644
index 0000000..39a278d
--- /dev/null
+++ b/scripts/coccinelle/swap_muldiv64.cocci
@@ -0,0 +1,46 @@
+// replace muldiv64(i32, i64, x) by muldiv64(i64, i32, x)
+@filter@
+typedef uint64_t;
+typedef int64_t;
+typedef uint32_t;
+typedef int32_t;
+uint64_t u64;
+int64_t s64;
+uint32_t u32;
+int32_t s32;
+int si;
+unsigned int ui;
+long sl;
+unsigned long ul;
+expression b;
+position p;
+@@
+	muldiv64(
+(
+si
+|
+ui
+|
+s32
+|
+u32
+)
+,
+(
+sl
+|
+ul
+|
+u64
+|
+s64
+)
+, b)@p
+
+@swap@
+position filter.p;
+expression a, b, c;
+@@
+
+-muldiv64(a,b,c)@p
++muldiv64(b,a,c)
-- 
2.5.5

[Qemu-devel] [PATCH 2/3] The only 64bit parameter of muldiv64() is the first one.

[Laurent Vivier]

muldiv64() is "uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)"

Some time it is used as muldiv64(uint32_t a, uint64_t b, uint32_t c)"

This patch is the result of coccinelle script
scripts/coccinelle/swap_muldiv64.cocci to reorder arguments.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 hw/timer/omap_gptimer.c | 4 ++--
 hw/usb/hcd-ohci.c       | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/timer/omap_gptimer.c b/hw/timer/omap_gptimer.c
index 3a43863..5e3e8a6 100644
--- a/hw/timer/omap_gptimer.c
+++ b/hw/timer/omap_gptimer.c
@@ -133,8 +133,8 @@ static inline void omap_gp_timer_update(struct omap_gp_timer_s *timer)
         timer_mod(timer->timer, timer->time + expires);
 
         if (timer->ce && timer->match_val >= timer->val) {
-            matches = muldiv64(timer->match_val - timer->val,
-                            timer->ticks_per_sec, timer->rate);
+            matches = muldiv64(timer->ticks_per_sec,
+                               timer->match_val - timer->val, timer->rate);
             timer_mod(timer->match, timer->time + matches);
         } else
             timer_del(timer->match);
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index ffab561..e5b535f 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -1474,7 +1474,7 @@ static uint32_t ohci_get_frame_remaining(OHCIState *ohci)
     if (tks >= usb_frame_time)
         return (ohci->frt << 31);
 
-    tks = muldiv64(1, tks, usb_bit_time);
+    tks = muldiv64(tks, 1, usb_bit_time);
     fr = (uint16_t)(ohci->fi - tks);
 
     return (ohci->frt << 31) | fr;
-- 
2.5.5

[Qemu-devel] [PATCH 3/3] remove useless muldiv64()

[Laurent Vivier]

muldiv64(a, 1, b) is like "a / b".

This patch is the result of coccinelle script
scripts/coccinelle/remove_muldiv64.cocci.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 hw/usb/hcd-ohci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index e5b535f..2af6c16 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -1474,7 +1474,7 @@ static uint32_t ohci_get_frame_remaining(OHCIState *ohci)
     if (tks >= usb_frame_time)
         return (ohci->frt << 31);
 
-    tks = muldiv64(tks, 1, usb_bit_time);
+    tks = tks / usb_bit_time;
     fr = (uint16_t)(ohci->fi - tks);
 
     return (ohci->frt << 31) | fr;
-- 
2.5.5

Re: [Qemu-devel] [PATCH 0/3] muldiv64() trivial fixes

[Richard Henderson]

On 05/04/2016 03:04 AM, Laurent Vivier wrote:
> Some fixes in the use of muldiv64()
>
> The patches have been generated with the help of coccinelle.
>
> The first patch contains the scripts used to generate the two following
> patches. As it is done for linux, I've added the scripts under
> scripts/coccinelle.
>
> Laurent Vivier (3):
>   scripts: add muldiv64() checking coccinelle scripts
>   The only 64bit parameter of muldiv64() is the first one.
>   remove useless muldiv64()

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~