Extend and simplify the sample profile input file.

1- Use the line_iterator class to read profile files.

2- Allow comments in profile file. Lines starting with '#'
   are completely ignored while reading the profile.

3- Add parsing support for discriminators and indirect call samples.

   Our external profiler can emit more profile information that we are
   currently not handling. This patch does not add new functionality to
   support this information, but it allows profile files to provide it.

   I will add actual support later on (for at least one of these
   features, I need support for DWARF discriminators in Clang).

   A sample line may contain the following additional information:

   Discriminator. This is used if the sampled program was compiled with
   DWARF discriminator support
   (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators). This
   is currently only emitted by GCC and we just ignore it.

   Potential call targets and samples. If present, this line contains a
   call instruction. This models both direct and indirect calls. Each
   called target is listed together with the number of samples. For
   example,

                    130: 7  foo:3  bar:2  baz:7

   The above means that at relative line offset 130 there is a call
   instruction that calls one of foo(), bar() and baz(). With baz()
   being the relatively more frequent call target.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2355

4- Simplify format of profile input file.

   This implements earlier suggestions to simplify the format of the
   sample profile file. The symbol table is not necessary and function
   profiles do not need to know the number of samples in advance.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2419

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198973 91177308-0d34-0410-b5e6-96231b3b80d8

9 files changed, 15 insertions, 35 deletions

diff --git a/test/Transforms/SampleProfile/Inputs/bad_fn_header.prof b/test/Transforms/SampleProfile/Inputs/bad_fn_header.prof
index 90459e65d0..763956f068 100644
--- a/test/Transforms/SampleProfile/Inputs/bad_fn_header.prof
+++ b/test/Transforms/SampleProfile/Inputs/bad_fn_header.prof
@@ -1,6 +1,3 @@
-symbol table
-1
-empty
 empty:100:BAD
 0: 0
 1: 100
diff --git a/test/Transforms/SampleProfile/Inputs/bad_sample_line.prof b/test/Transforms/SampleProfile/Inputs/bad_sample_line.prof
index 8c0d7630f9..038c45f77e 100644
--- a/test/Transforms/SampleProfile/Inputs/bad_sample_line.prof
+++ b/test/Transforms/SampleProfile/Inputs/bad_sample_line.prof
@@ -1,6 +1,3 @@
-symbol table
-1
-empty
-empty:100:0:1
+empty:100:0
 0: 0
 1: BAD
diff --git a/test/Transforms/SampleProfile/Inputs/branch.prof b/test/Transforms/SampleProfile/Inputs/branch.prof
index d19894d428..cd1cb5b1f1 100644
--- a/test/Transforms/SampleProfile/Inputs/branch.prof
+++ b/test/Transforms/SampleProfile/Inputs/branch.prof
@@ -1,7 +1,4 @@
-symbol table
-1
-main
-main:15680:0:7
+main:15680:0
 0: 0
 4: 0
 7: 0
diff --git a/test/Transforms/SampleProfile/Inputs/calls.prof b/test/Transforms/SampleProfile/Inputs/calls.prof
new file mode 100644
index 0000000000..251cb538ef
--- /dev/null
+++ b/test/Transforms/SampleProfile/Inputs/calls.prof
@@ -0,0 +1,11 @@
+_Z3sumii:105580:5279
+0: 5279
+1: 5279
+2: 5279
+main:225715:0
+2: 5553
+3: 5391
+# This indicates that at line 3 of this function, the 'then' branch
+# of the conditional is taken (discriminator '1'). However, we still
+# do not handle this case, so we compute the wrong branch weights here.
+3.1: 5752  _Z3sumii:5860
diff --git a/test/Transforms/SampleProfile/Inputs/missing_num_syms.prof b/test/Transforms/SampleProfile/Inputs/missing_num_syms.prof
deleted file mode 100644
index 7cd053611c..0000000000
--- a/test/Transforms/SampleProfile/Inputs/missing_num_syms.prof
+++ /dev/null
@@ -1,5 +0,0 @@
-symbol table
-empty
-empty:100:0:1
-0: 0
-1: 100
diff --git a/test/Transforms/SampleProfile/Inputs/missing_samples.prof b/test/Transforms/SampleProfile/Inputs/missing_samples.prof
deleted file mode 100644
index edd36c2f52..0000000000
--- a/test/Transforms/SampleProfile/Inputs/missing_samples.prof
+++ /dev/null
@@ -1,6 +0,0 @@
-symbol table
-1
-empty
-empty:100:0:10
-0: 0
-1: 100
diff --git a/test/Transforms/SampleProfile/Inputs/missing_symtab.prof b/test/Transforms/SampleProfile/Inputs/missing_symtab.prof
deleted file mode 100644
index 2a826138b0..0000000000
--- a/test/Transforms/SampleProfile/Inputs/missing_symtab.prof
+++ /dev/null
@@ -1,5 +0,0 @@
-1
-empty
-empty:100:0:1
-0: 0
-1: 100
diff --git a/test/Transforms/SampleProfile/Inputs/propagate.prof b/test/Transforms/SampleProfile/Inputs/propagate.prof
index ea799e93ee..b28609be66 100644
--- a/test/Transforms/SampleProfile/Inputs/propagate.prof
+++ b/test/Transforms/SampleProfile/Inputs/propagate.prof
@@ -1,7 +1,4 @@
-symbol table
-1
-_Z3fooiil
-_Z3fooiil:58139:0:16
+_Z3fooiil:58139:0
 0: 0
 1: 0
 2: 0
diff --git a/test/Transforms/SampleProfile/Inputs/syntax.prof b/test/Transforms/SampleProfile/Inputs/syntax.prof
index 9280751b2d..f3738912a9 100644
--- a/test/Transforms/SampleProfile/Inputs/syntax.prof
+++ b/test/Transforms/SampleProfile/Inputs/syntax.prof
@@ -1,6 +1,3 @@
-symbol table
-1
-empty
-empty:100:0:2
+empty:100:0
 0: 0
 1: 100