/* params.def - Run-time parameters.
- Copyright (C) 2001 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002 Free Software Foundation, Inc.
Written by Mark Mitchell <mark@codesourcery.com>.
This file is part of GCC.
Be sure to add an entry to invoke.texi summarizing the parameter. */
-/* The maximum number of instructions accepted for inlining a
- function. Increasing values mean more agressive inlining.
- This affects currently only functions explicitly marked as
- inline (or methods defined within the class definition for C++).
- The original default value of 10000 was arbitrary and caused
- significant compile-time performance regressions. */
+/* The single function inlining limit. This is the maximum size
+ of a function counted in internal gcc instructions (not in
+ real machine instructions) that is eligible for inlining
+ by the tree inliner.
+ The default value is 300.
+ Only functions marked inline (or methods defined in the class
+ definition for C++) are affected by this, unless you set the
+ -finline-functions (included in -O3) compiler option.
+ There are more restrictions to inlining: If inlined functions
+ call other functions, the already inlined instructions are
+ counted and once the recursive inline limit (see
+ "max-inline-insns" parameter) is exceeded, the acceptable size
+ gets decreased. */
+DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
+ "max-inline-insns-single",
+ "The maximum number of instructions in a single function eliglible for inlining",
+ 300)
+
+/* The repeated inlining limit. After this number of instructions
+ (in the internal gcc representation, not real machine instructions)
+ got inlined by repeated inlining, gcc starts to decrease the maximum
+ number of inlinable instructions in the tree inliner.
+ This is done by a linear function, see "max-inline-slope" parameter.
+ It is necessary in order to limit the compile-time resources, that
+ could otherwise become very high.
+ It is recommended to set this value to twice the value of the single
+ function limit (set by the "max-inline-insns-single" parameter) or
+ higher. The default value is 600.
+ Higher values mean that more inlining is done, resulting in
+ better performance of the code, at the expense of higher
+ compile-time resource (time, memory) requirements and larger
+ binaries.
+ This parameters also controls the maximum size of functions considered
+ for inlining in the RTL inliner. */
DEFPARAM (PARAM_MAX_INLINE_INSNS,
"max-inline-insns",
- "The maximum number of instructions in a function that is eligible for inlining",
+ "The maximuem number of instructions by repeated inlining before gcc starts to throttle inlining",
600)
+/* After the repeated inline limit has been exceeded (see
+ "max-inline-insns" parameter), a linear function is used to
+ decrease the size of single functions eligible for inlining.
+ The slope of this linear function is given the negative
+ reciprocal value (-1/x) of this parameter.
+ The default vlue is 32.
+ This linear function is used until it falls below a minimum
+ value specified by the "min-inline-insns" parameter. */
+DEFPARAM (PARAM_MAX_INLINE_SLOPE,
+ "max-inline-slope",
+ "The slope of the linear funtion throttling inlining after the recursive inlining limit has been reached is given by the negative reciprocal value of this parameter",
+ 32)
+
+/* When gcc has inlined so many instructions (by repeated
+ inlining) that the throttling limits the inlining very much,
+ inlining for very small functions is still desirable to
+ achieve good runtime performance. The size of single functions
+ (measured in gcc instructions) which will still be eligible for
+ inlining then is given by this parameter. It defaults to 130.
+ Only much later (after exceeding 128 times the recursive limit)
+ inlining is cut down completely. */
+DEFPARAM (PARAM_MIN_INLINE_INSNS,
+ "min-inline-insns",
+ "The number of instructions in a single functions still eligible to inlining after a lot recursive inlining",
+ 130)
+
/* The maximum number of instructions to consider when looking for an
instruction to fill a delay slot. If more than this arbitrary
number of instructions is searched, the time savings from filling
"max-gcse-memory",
"The maximum amount of memory to be allocated by GCSE",
50 * 1024 * 1024)
-/* The number of repetitions of copy/const prop and PRE to run. */
+/* The number of repetitions of copy/const prop and PRE to run. */
DEFPARAM(PARAM_MAX_GCSE_PASSES,
"max-gcse-passes",
"The maximum number of passes to make when doing GCSE",
"max-unrolled-insns",
"The maximum number of instructions to consider to unroll in a loop",
100)
+
+/* The maximum number of insns of an unswitched loop. */
+DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
+ "max-unswitch-insns",
+ "The maximum number of insns of an unswitched loop",
+ 50)
+/* The maximum level of recursion in unswitch_single_loop. */
+DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
+ "max-unswitch-level",
+ "The maximum number of unswitchings in a single loop",
+ 3)
+
+DEFPARAM(HOT_BB_COUNT_FRACTION,
+ "hot-bb-count-fraction",
+ "Select fraction of the maximal count of repetitions of basic block in \
+program given basic block needs to have to be considered hot",
+ 10000)
+DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
+ "hot-bb-frequency-fraction",
+ "Select fraction of the maximal frequency of executions of basic \
+block in function given basic block needs to have to be considered hot",
+ 1000)
+DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
+ "tracer-dynamic-coverage-feedback",
+ "The percentage of function, weighted by execution frequency, that \
+must be covered by trace formation. Used when profile feedback is available",
+ 95)
+DEFPARAM(TRACER_DYNAMIC_COVERAGE,
+ "tracer-dynamic-coverage",
+ "The percentage of function, weighted by execution frequency, that \
+must be covered by trace formation. Used when profile feedback is not available",
+ 75)
+DEFPARAM(TRACER_MAX_CODE_GROWTH,
+ "tracer-max-code-growth",
+ "Maximal code growth caused by tail duplication (in percents)",
+ 100)
+DEFPARAM(TRACER_MIN_BRANCH_RATIO,
+ "tracer-min-branch-ratio",
+ "Stop reverse growth if the reverse probability of best edge is less \
+than this threshold (in percents)",
+ 10)
+DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
+ "tracer-min-branch-probability-feedback",
+ "Stop forward growth if the probability of best edge is less than \
+this threshold (in percents). Used when profile feedback is available",
+ 80)
+DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
+ "tracer-min-branch-probability",
+ "Stop forward growth if the probability of best edge is less than \
+this threshold (in percents). Used when profile feedback is not available",
+ 50)
+
+/* The maximum number of incoming edges to consider for crossjumping. */
+DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
+ "max-crossjump-edges",
+ "The maximum number of incoming edges to consider for crossjumping",
+ 100)
+
+#ifdef ENABLE_GC_ALWAYS_COLLECT
+# define GGC_MIN_EXPAND_DEFAULT 0
+# define GGC_MIN_HEAPSIZE_DEFAULT 0
+#else
+# define GGC_MIN_EXPAND_DEFAULT 30
+# define GGC_MIN_HEAPSIZE_DEFAULT 4096
+#endif
+
+DEFPARAM(GGC_MIN_EXPAND,
+ "ggc-min-expand",
+ "Minimum heap expansion to trigger garbage collection, as \
+a percentage of the total size of the heap.",
+ GGC_MIN_EXPAND_DEFAULT)
+
+DEFPARAM(GGC_MIN_HEAPSIZE,
+ "ggc-min-heapsize",
+ "Minimum heap size before we start collecting garbage, in kilobytes.",
+ GGC_MIN_HEAPSIZE_DEFAULT)
+
+#undef GGC_MIN_EXPAND_DEFAULT
+#undef GGC_MIN_HEAPSIZE_DEFAULT
+
/*
Local variables:
mode:c
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