Summary:
Previously we were doing 1 << S. "1" is an int, so this doesn't work
when S >= 32.
This patch also adds some static_asserts to these functions to ensure
that we don't hit UB by shifting left too much.
Reviewers: rnk
Subscribers: llvm-commits, dylanmckay
Differential Revision: https://reviews.llvm.org/D22441
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275719 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This shift is undefined behavior (and, as compiled by clang, gives the
wrong answer for maxUIntN(64)).
Reviewers: mkuper
Subscribers: llvm-commits, jroelofs, rsmith
Differential Revision: https://reviews.llvm.org/D22430
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275656 91177308-0d34-0410-b5e6-96231b3b80d8
In r271380, I added several functions to get the minimum/maximum values
of n-width integers.
This just adds tests for them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271505 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Add SaturatingMultiplyAdd convenience function template since A + (X * Y) comes up frequently when doing weighted arithmetic.
Reviewers: davidxl, silvas
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15385
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257532 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Improve SaturatingAdd()/SaturatingMultiply() to use bool * to optionally return overflow result.
This should make it clearer that the value is returned at callsites and reduces the size of the implementation.
Reviewers: davidxl, silvas
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15219
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255128 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Adds the ability for callers to detect when saturation occurred on the result of saturating addition/multiplication.
Reviewers: davidxl, silvas, rsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14931
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253921 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change fixes the SaturatingMultiply<T>() function template to not cause undefined behavior with T=uint16_t.
Thanks to Richard Smith's contribution, it also no longer requires an integer division.
Patch by Richard Smith.
Reviewers: silvas, davidxl
Subscribers: rsmith, davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14845
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253870 91177308-0d34-0410-b5e6-96231b3b80d8
Ubsan detected undefined behavior in the MathExtras SaturatingMultiply test.
This change disables the test while it is being investigated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253539 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change adds MathExtras helper functions for handling unsigned, saturating addition and multiplication. It also updates the instrumentation and sample profile merge implementations to use them.
Reviewers: dnovillo, bogner, davidxl
Subscribers: davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14720
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253497 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change adds MathExtras helper functions for handling unsigned, saturating addition and multiplication. It also updates the instrumentation and sample profile merge implementations to use them.
No functional changes.
Reviewers: dnovillo, bogner, davidxl
Subscribers: davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14720
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253412 91177308-0d34-0410-b5e6-96231b3b80d8
HHVM calling convention, hhvmcc, is used by HHVM JIT for
functions in translated cache. We currently support LLVM back end to
generate code for X86-64 and may support other architectures in the
future.
In HHVM calling convention any GP register could be used to pass and
return values, with the exception of R12 which is reserved for
thread-local area and is callee-saved. Other than R12, we always
pass RBX and RBP as args, which are our virtual machine's stack pointer
and frame pointer respectively.
When we enter translation cache via hhvmcc function, we expect
the stack to be aligned at 16 bytes, i.e. skewed by 8 bytes as opposed
to standard ABI alignment. This affects stack object alignment and stack
adjustments for function calls.
One extra calling convention, hhvm_ccc, is used to call C++ helpers from
HHVM's translation cache. It is almost identical to standard C calling
convention with an exception of first argument which is passed in RBP
(before we use RDI, RSI, etc.)
Differential Revision: http://reviews.llvm.org/D12681
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248832 91177308-0d34-0410-b5e6-96231b3b80d8
0xFFFFFFFFFFFFFFFFLL doesn't fit in a long long so it should have
type 'unsigned long long'. MSVC thinks it's a (signed) __int64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228950 91177308-0d34-0410-b5e6-96231b3b80d8
