From b5173c8d45bbb1eae9900eea6231823041cac64f Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Thu, 18 Feb 2021 17:10:44 -0800 Subject: Export of internal Abseil changes -- f27dbf50d5db12279ab018f11c93ad1704043006 by Derek Mauro : Internal change PiperOrigin-RevId: 358298501 -- 864c141a59e20e96234c06700d7519d43bc73d71 by Derek Mauro : Annotates the duration-to-int64 and duration-to-double conversion functions as "pure" to potentially optimize out repeated calls with the same argument This adds an ABSL_ATTRIBUTE_PURE_FUNCTION macro for this purpose. PiperOrigin-RevId: 358247225 GitOrigin-RevId: f27dbf50d5db12279ab018f11c93ad1704043006 Change-Id: I5c2238911711b15d9d3ae53da44db788f20b402b --- absl/base/attributes.h | 21 +++++++++++++++++++ absl/debugging/internal/stacktrace_powerpc-inl.inc | 5 +++-- absl/time/time.h | 24 +++++++++++----------- 3 files changed, 36 insertions(+), 14 deletions(-) diff --git a/absl/base/attributes.h b/absl/base/attributes.h index faa5b27e..cf2cb550 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -678,4 +678,25 @@ #define ABSL_CONST_INIT #endif // ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization) +// ABSL_ATTRIBUTE_PURE_FUNCTION +// +// ABSL_ATTRIBUTE_PURE_FUNCTION is used to annotate declarations of "pure" +// functions. A function is pure if its return value is only a function of its +// arguments. The pure attribute prohibits a function from modifying the state +// of the program that is observable by means other than inspecting the +// function's return value. Declaring such functions with the pure attribute +// allows the compiler to avoid emitting some calls in repeated invocations of +// the function with the same argument values. +// +// Example: +// +// ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Milliseconds(Duration d); +#if ABSL_HAVE_CPP_ATTRIBUTE(gnu::pure) +#define ABSL_ATTRIBUTE_PURE_FUNCTION [[gnu::pure]] +#elif ABSL_HAVE_ATTRIBUTE(pure) +#define ABSL_ATTRIBUTE_PURE_FUNCTION __attribute__((pure)) +#else +#define ABSL_ATTRIBUTE_PURE_FUNCTION +#endif + #endif // ABSL_BASE_ATTRIBUTES_H_ diff --git a/absl/debugging/internal/stacktrace_powerpc-inl.inc b/absl/debugging/internal/stacktrace_powerpc-inl.inc index 5b2cdc2a..cf8c0516 100644 --- a/absl/debugging/internal/stacktrace_powerpc-inl.inc +++ b/absl/debugging/internal/stacktrace_powerpc-inl.inc @@ -132,9 +132,10 @@ static void **NextStackFrame(void **old_sp, const void *uc) { reinterpret_cast(uc); void **const sp_before_signal = #if defined(__PPC64__) - reinterpret_cast(signal_context->uc_mcontext.gp_regs[PT_R1]); + reinterpret_cast(signal_context->uc_mcontext.gp_regs[PT_R1]); #else - reinterpret_cast(signal_context->uc_mcontext.uc_regs->gregs[PT_R1]); + reinterpret_cast( + signal_context->uc_mcontext.uc_regs->gregs[PT_R1]); #endif // Check that alleged sp before signal is nonnull and is reasonably // aligned. diff --git a/absl/time/time.h b/absl/time/time.h index 72508031..d9ad1aed 100644 --- a/absl/time/time.h +++ b/absl/time/time.h @@ -458,12 +458,12 @@ Duration Hours(T n) { // // absl::Duration d = absl::Milliseconds(1500); // int64_t isec = absl::ToInt64Seconds(d); // isec == 1 -int64_t ToInt64Nanoseconds(Duration d); -int64_t ToInt64Microseconds(Duration d); -int64_t ToInt64Milliseconds(Duration d); -int64_t ToInt64Seconds(Duration d); -int64_t ToInt64Minutes(Duration d); -int64_t ToInt64Hours(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Nanoseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Microseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Milliseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Seconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Minutes(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION int64_t ToInt64Hours(Duration d); // ToDoubleNanoSeconds() // ToDoubleMicroseconds() @@ -480,12 +480,12 @@ int64_t ToInt64Hours(Duration d); // // absl::Duration d = absl::Milliseconds(1500); // double dsec = absl::ToDoubleSeconds(d); // dsec == 1.5 -double ToDoubleNanoseconds(Duration d); -double ToDoubleMicroseconds(Duration d); -double ToDoubleMilliseconds(Duration d); -double ToDoubleSeconds(Duration d); -double ToDoubleMinutes(Duration d); -double ToDoubleHours(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleNanoseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleMicroseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleMilliseconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleSeconds(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleMinutes(Duration d); +ABSL_ATTRIBUTE_PURE_FUNCTION double ToDoubleHours(Duration d); // FromChrono() // -- cgit v1.2.3