From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Subject: [PULL 15/28] osdep: provide ROUND_DOWN macro
Date: Fri, 25 Jun 2021 16:18:09 +0200 [thread overview]
Message-ID: <20210625141822.1368639-16-pbonzini@redhat.com> (raw)
In-Reply-To: <20210625141822.1368639-1-pbonzini@redhat.com>
osdep.h provides a ROUND_UP macro to hide bitwise operations for the
purpose of rounding a number up to a power of two; add a ROUND_DOWN
macro that does the same with truncation towards zero.
While at it, change the formatting of some comments.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/qemu/osdep.h | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 0a54bf7be8..c3656b755a 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -319,11 +319,16 @@ extern "C" {
})
#endif
-/* Round number down to multiple */
+/*
+ * Round number down to multiple. Safe when m is not a power of 2 (see
+ * ROUND_DOWN for a faster version when a power of 2 is guaranteed).
+ */
#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
-/* Round number up to multiple. Safe when m is not a power of 2 (see
- * ROUND_UP for a faster version when a power of 2 is guaranteed) */
+/*
+ * Round number up to multiple. Safe when m is not a power of 2 (see
+ * ROUND_UP for a faster version when a power of 2 is guaranteed).
+ */
#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
/* Check if n is a multiple of m */
@@ -340,11 +345,22 @@ extern "C" {
/* Check if pointer p is n-bytes aligned */
#define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
-/* Round number up to multiple. Requires that d be a power of 2 (see
+/*
+ * Round number down to multiple. Requires that d be a power of 2 (see
* QEMU_ALIGN_UP for a safer but slower version on arbitrary
- * numbers); works even if d is a smaller type than n. */
+ * numbers); works even if d is a smaller type than n.
+ */
+#ifndef ROUND_DOWN
+#define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d)))
+#endif
+
+/*
+ * Round number up to multiple. Requires that d be a power of 2 (see
+ * QEMU_ALIGN_UP for a safer but slower version on arbitrary
+ * numbers); works even if d is a smaller type than n.
+ */
#ifndef ROUND_UP
-#define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
+#define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
#endif
#ifndef DIV_ROUND_UP
--
2.31.1
next prev parent reply other threads:[~2021-06-25 14:29 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-25 14:17 [PULL v2 00/28] Misc (including block file-posix) for 2021-06-23 Paolo Bonzini
2021-06-25 14:17 ` [PULL 01/28] target/i386: kvm: add support for TSC scaling Paolo Bonzini
2021-06-25 14:17 ` [PULL 02/28] meson: drop unused CONFIG_GCRYPT_HMAC Paolo Bonzini
2021-06-25 14:17 ` [PULL 03/28] configure: drop unused variables for xts Paolo Bonzini
2021-06-25 14:17 ` [PULL 04/28] meson: remove preadv from summary Paolo Bonzini
2021-06-25 14:17 ` [PULL 05/28] tests: remove QCRYPTO_HAVE_TLS_TEST_SUPPORT Paolo Bonzini
2021-06-25 14:18 ` [PULL 06/28] configure, meson: convert crypto detection to meson Paolo Bonzini
2021-06-25 14:18 ` [PULL 07/28] configure, meson: convert libtasn1 " Paolo Bonzini
2021-06-25 14:18 ` [PULL 08/28] configure, meson: convert pam " Paolo Bonzini
2021-06-25 14:18 ` [PULL 09/28] configure, meson: convert libusb " Paolo Bonzini
2021-06-25 14:18 ` [PULL 10/28] configure, meson: convert libcacard " Paolo Bonzini
2021-06-25 14:18 ` [PULL 11/28] configure, meson: convert libusbredir " Paolo Bonzini
2021-06-25 14:18 ` [PULL 12/28] KVM: Fix dirty ring mmap incorrect size due to renaming accident Paolo Bonzini
2021-06-25 14:18 ` [PULL 13/28] file-posix: fix max_iov for /dev/sg devices Paolo Bonzini
2021-06-25 14:18 ` [PULL 14/28] scsi-generic: pass max_segments via max_iov field in BlockLimits Paolo Bonzini
2021-06-25 14:18 ` Paolo Bonzini [this message]
2021-06-29 4:12 ` [PULL 15/28] osdep: provide ROUND_DOWN macro Philippe Mathieu-Daudé
2021-06-25 14:18 ` [PULL 16/28] block-backend: align max_transfer to request alignment Paolo Bonzini
2021-06-25 14:18 ` [PULL 17/28] block: add max_hw_transfer to BlockLimits Paolo Bonzini
2021-06-25 14:18 ` [PULL 18/28] file-posix: try BLKSECTGET on block devices too, do not round to power of 2 Paolo Bonzini
2021-09-06 14:24 ` Halil Pasic
2021-09-22 19:51 ` Halil Pasic
2021-09-23 9:18 ` Recent qemu patch results in aio failures with host DASD disks resulting in guest I/O errors Christian Borntraeger
2021-09-23 10:57 ` [PULL 18/28] file-posix: try BLKSECTGET on block devices too, do not round to power of 2 Paolo Bonzini
2021-09-23 12:13 ` Halil Pasic
2021-09-23 13:02 ` Paolo Bonzini
2021-06-25 14:18 ` [PULL 19/28] block: feature detection for host block support Paolo Bonzini
2021-06-25 14:18 ` [PULL 20/28] block: check for sys/disk.h Paolo Bonzini
2021-06-25 14:18 ` [PULL 21/28] block: try BSD disk size ioctls one after another Paolo Bonzini
2021-06-25 14:18 ` [PULL 22/28] block: detect DKIOCGETBLOCKCOUNT/SIZE before use Paolo Bonzini
2021-06-25 14:18 ` [PULL 23/28] file-posix: handle EINTR during ioctl Paolo Bonzini
2021-06-25 14:18 ` [PULL 24/28] machine: move dies from X86MachineState to CpuTopology Paolo Bonzini
2021-06-25 14:18 ` [PULL 25/28] machine: move common smp_parse code to caller Paolo Bonzini
2021-06-25 14:18 ` [PULL 26/28] machine: add error propagation to mc->smp_parse Paolo Bonzini
2021-06-25 14:18 ` [PULL 27/28] machine: pass QAPI struct " Paolo Bonzini
2021-06-25 14:18 ` [PULL 28/28] machine: reject -smp dies!=1 for non-PC machines Paolo Bonzini
2021-06-29 8:37 ` [PULL v2 00/28] Misc (including block file-posix) for 2021-06-23 Peter Maydell
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