[llvm-commits] [llvm-gcc-4.2] r79556 - in /llvm-gcc-4.2/trunk/gcc: llvm-backend.cpp opts.c tree.c tree.h

[Dale Johannesen]

Author: johannes
Date: Thu Aug 20 13:28:41 2009
New Revision: 79556

URL: http://llvm.org/viewvc/llvm-project?rev=79556&view=rev
Log:
Hook up -finline-limit so it controls llvm's inlining.
Mapping is not exact, to put it mildly.  Should be
no functional change unless -finline-limit
(or --param max-inline-insns-auto) is used.


Modified:
    llvm-gcc-4.2/trunk/gcc/llvm-backend.cpp
    llvm-gcc-4.2/trunk/gcc/opts.c
    llvm-gcc-4.2/trunk/gcc/tree.c
    llvm-gcc-4.2/trunk/gcc/tree.h

Modified: llvm-gcc-4.2/trunk/gcc/llvm-backend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-backend.cpp?rev=79556&r1=79555&r2=79556&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-backend.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-backend.cpp Thu Aug 20 13:28:41 2009
@@ -351,6 +351,32 @@
 #undef Declare2
 }
 
+// GuessAtInliningThreshold - Figure out a reasonable threshold to pass llvm's
+// inliner.  There are 12 user-settable gcc params that affect inlining.  llvm
+// (so far) only has one knob; the param that corresponds most closely, and
+// which we use, is max-inline-insns-auto (set by -finline-limit, which is
+// what most users actually use).  This maps only very approximately to what
+// llvm's inliner is doing, but it's the best we've got.
+static unsigned GuessAtInliningThreshold() {
+  unsigned threshold = 200;
+  // Get the default value for gcc's max-inline-insns-auto.  This is the value
+  // after all language and target dependent changes to the global default are
+  // applied, but before parsing the command line.
+  unsigned default_miia = default_max_inline_insns_auto;
+  // See if the actual value is the same as the default.
+  unsigned miia = MAX_INLINE_INSNS_AUTO;
+  if (miia == default_miia) {
+    if (optimize_size || optimize < 3)
+      // Reduce inline limit.
+      threshold = 50;
+  } else {
+    // We have an overriding user-specified value.  Multiply by 20/9, which is
+    // the Magic Number converting 90 to 200.
+    threshold = miia * 20 / 9;
+  }
+  return threshold;
+}
+
 void llvm_initialize_backend(void) {
   // Initialize the LLVM backend.
 #define DoInit2(TARG, MOD)  LLVMInitialize ## TARG ## MOD()
@@ -394,9 +420,6 @@
     Args.push_back("--debug-pass=Structure");
   if (flag_debug_pass_arguments)
     Args.push_back("--debug-pass=Arguments");
-  if (optimize_size || optimize < 3)
-    // Reduce inline limit. Default limit is 200.
-    Args.push_back("--inline-threshold=50");
   if (flag_unwind_tables)
     Args.push_back("--unwind-tables");
 
@@ -405,6 +428,12 @@
   // purposes, and shouldn't really be for general use.
   std::vector<std::string> ArgStrings;
 
+  if (flag_inline_trees > 1) {
+    unsigned threshold = GuessAtInliningThreshold();
+    std::string Arg("--inline-threshold="+utostr(threshold));
+    ArgStrings.push_back(Arg);
+  }
+
   if (flag_limited_precision > 0) {
     std::string Arg("--limit-float-precision="+utostr(flag_limited_precision));
     ArgStrings.push_back(Arg);

Modified: llvm-gcc-4.2/trunk/gcc/opts.c
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/opts.c?rev=79556&r1=79555&r2=79556&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/opts.c (original)
+++ llvm-gcc-4.2/trunk/gcc/opts.c Thu Aug 20 13:28:41 2009
@@ -682,6 +682,12 @@
   OPTIMIZATION_OPTIONS (optimize, optimize_size);
 #endif
 
+  /* LLVM LOCAL begin hook up -finline-limit */
+  /* Remember the value of MAX_INLINE_INSNS_AUTO after applying target-dependent
+     changes to the defaults, but before command line options are parsed. */
+  default_max_inline_insns_auto = MAX_INLINE_INSNS_AUTO;
+  /* LLVM LOCAL end */
+
   /* APPLE LOCAL begin AV 3846092 */
   /* We have apple local patch to disable -fstrict-aliasing when -O2 is used.
      However do not disable it when -ftree-vectorize is used. Clobber its value

Modified: llvm-gcc-4.2/trunk/gcc/tree.c
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/tree.c?rev=79556&r1=79555&r2=79556&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/tree.c (original)
+++ llvm-gcc-4.2/trunk/gcc/tree.c Thu Aug 20 13:28:41 2009
@@ -73,6 +73,13 @@
 tree generic_block_literal_struct_type;
 /* APPLE LOCAL end 6353006  */
 
+/* LLVM LOCAL begin */
+/* The value of MAX_INLINE_INSNS_AUTO after all target-dependent changes
+   are applied to the global default (which many targets do), but before
+   command line flags are handled. */
+unsigned default_max_inline_insns_auto;
+/* LLVM LOCAL end */
+
 /* obstack.[ch] explicitly declined to prototype this.  */
 extern int _obstack_allocated_p (struct obstack *h, void *obj);
 

Modified: llvm-gcc-4.2/trunk/gcc/tree.h
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/tree.h?rev=79556&r1=79555&r2=79556&view=diff

==============================================================================
--- llvm-gcc-4.2/trunk/gcc/tree.h (original)
+++ llvm-gcc-4.2/trunk/gcc/tree.h Thu Aug 20 13:28:41 2009
@@ -4892,4 +4892,10 @@
 
 /* APPLE LOCAL end radar 6300081  */
 
+/* LLVM LOCAL begin */
+/* The value of MAX_INLINE_INSNS_AUTO after all target-dependent changes
+   are applied to the global default (which many targets do), but before
+   command line flags are handled. */
+extern unsigned default_max_inline_insns_auto;
+/* LLVM LOCAL end */
 #endif  /* GCC_TREE_H  */