compiler: permit inlining temporary statements and references

    
    This increases the number of inlinable functions from 439 to 455.
    An example is math/bits.Mul32, which uses temporaries to handle the
    tuple assignment.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180837

From-SVN: r272022

1 files changed, 15 insertions, 1 deletions

diff --git a/gcc/go/gofrontend/export.h b/gcc/go/gofrontend/export.h
index e3932d4..92d0180 100644
--- a/gcc/go/gofrontend/export.h
+++ b/gcc/go/gofrontend/export.h
@@ -20,6 +20,7 @@ class Type;
 class Package;
 class Import_init_set;
 class Backend;
+class Temporary_statement;
 
 // Codes used for the builtin types.  These are all negative to make
 // them easily distinct from the codes assigned by Export::write_type.
@@ -307,7 +308,8 @@ class Export_function_body : public String_dump
 {
  public:
   Export_function_body(Export* exp, int indent)
-    : exp_(exp), type_context_(NULL), indent_(indent)
+    : exp_(exp), body_(), type_context_(NULL), next_temporary_index_(0),
+      temporary_indexes_(), indent_(indent)
   { }
 
   // Write a character to the body.
@@ -363,6 +365,14 @@ class Export_function_body : public String_dump
   package_index(const Package* p) const
   { return this->exp_->package_index(p); }
 
+  // Record a temporary statement and return its index.
+  unsigned int
+  record_temporary(const Temporary_statement*);
+
+  // Return the index of a temporary statement.
+  unsigned int
+  temporary_index(const Temporary_statement*);
+
   // Return a reference to the completed body.
   const std::string&
   body() const
@@ -375,6 +385,10 @@ class Export_function_body : public String_dump
   std::string body_;
   // Current type context.  Used to avoid duplicate type conversions.
   Type* type_context_;
+  // Index to give to next temporary statement.
+  unsigned int next_temporary_index_;
+  // Map temporary statements to indexes.
+  Unordered_map(const Temporary_statement*, unsigned int) temporary_indexes_;
   // Current indentation level: the number of spaces before each statement.
   int indent_;
 };