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| author | Radim Krčmář <rkrcmar@redhat.com> | 2015-02-17 17:30:52 +0100 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2015-03-03 08:33:08 +0100 |
| commit | bb7443f6d6f09411ea10f06e6cb0d416bd1ccebd (patch) | |
| tree | 3d01f66f23e0bc87df16713247ee40fc075d9586 | |
| parent | 876d516311c1538a7d29f2abec48b7cda0645eea (diff) | |
| download | qemu-bb7443f6d6f09411ea10f06e6cb0d416bd1ccebd.zip qemu-bb7443f6d6f09411ea10f06e6cb0d416bd1ccebd.tar.gz qemu-bb7443f6d6f09411ea10f06e6cb0d416bd1ccebd.tar.bz2 | |
qxl: refactor rounding up to a nearest power of 2
We already have pow2floor, mirror it and use instead of a function with
similar results (same in used domain), to clarify our intent.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | hw/display/qxl.c | 23 | ||||
| -rw-r--r-- | include/qemu-common.h | 3 | ||||
| -rw-r--r-- | util/cutils.c | 14 |
3 files changed, 22 insertions, 18 deletions
diff --git a/hw/display/qxl.c b/hw/display/qxl.c index 92f2d50..94ff52a 100644 --- a/hw/display/qxl.c +++ b/hw/display/qxl.c @@ -300,19 +300,6 @@ void qxl_spice_reset_cursor(PCIQXLDevice *qxl) qxl->ssd.cursor = cursor_builtin_hidden(); } - -static inline uint32_t msb_mask(uint32_t val) -{ - uint32_t mask; - - do { - mask = ~(val - 1) & val; - val &= ~mask; - } while (mask < val); - - return mask; -} - static ram_addr_t qxl_rom_size(void) { uint32_t required_rom_size = sizeof(QXLRom) + sizeof(QXLModes) + @@ -1921,10 +1908,10 @@ static void qxl_init_ramsize(PCIQXLDevice *qxl) qxl->vram32_size = 4096; qxl->vram_size = 4096; } - qxl->vgamem_size = msb_mask(qxl->vgamem_size * 2 - 1); - qxl->vga.vram_size = msb_mask(qxl->vga.vram_size * 2 - 1); - qxl->vram32_size = msb_mask(qxl->vram32_size * 2 - 1); - qxl->vram_size = msb_mask(qxl->vram_size * 2 - 1); + qxl->vgamem_size = pow2ceil(qxl->vgamem_size); + qxl->vga.vram_size = pow2ceil(qxl->vga.vram_size); + qxl->vram32_size = pow2ceil(qxl->vram32_size); + qxl->vram_size = pow2ceil(qxl->vram_size); } static int qxl_init_common(PCIQXLDevice *qxl) @@ -1956,7 +1943,7 @@ static int qxl_init_common(PCIQXLDevice *qxl) break; case 4: /* qxl-4 */ pci_device_rev = QXL_REVISION_STABLE_V12; - io_size = msb_mask(QXL_IO_RANGE_SIZE * 2 - 1); + io_size = pow2ceil(QXL_IO_RANGE_SIZE); break; default: error_report("Invalid revision %d for qxl device (max %d)", diff --git a/include/qemu-common.h b/include/qemu-common.h index 644b46d..1b5cffb 100644 --- a/include/qemu-common.h +++ b/include/qemu-common.h @@ -418,6 +418,9 @@ static inline bool is_power_of_2(uint64_t value) /* round down to the nearest power of 2*/ int64_t pow2floor(int64_t value); +/* round up to the nearest power of 2 (0 if overflow) */ +uint64_t pow2ceil(uint64_t value); + #include "qemu/module.h" /* diff --git a/util/cutils.c b/util/cutils.c index dbe7412..c2250d1 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -483,6 +483,20 @@ int64_t pow2floor(int64_t value) return value; } +/* round up to the nearest power of 2 (0 if overflow) */ +uint64_t pow2ceil(uint64_t value) +{ + uint8_t nlz = clz64(value); + + if (is_power_of_2(value)) { + return value; + } + if (!nlz) { + return 0; + } + return 1ULL << (64 - nlz); +} + /* * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128) * Input is limited to 14-bit numbers |