Add two new pragmas for controlling software pipelining optimizations.

This patch adds #pragma clang loop pipeline and #pragma clang loop pipeline_initiation_interval for debugging or reducing compile time purposes. It is possible to disable SWP for concrete loops to save compilation time or to find bugs by not doing SWP to certain loops. It is possible to set value of initiation interval to concrete number to save compilation time by not doing extra pipeliner passes or to check created schedule for specific initiation interval.

Patch by Alexey Lapshin.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@350414 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 24 insertions, 12 deletions

diff --git a/lib/Parse/ParsePragma.cpp b/lib/Parse/ParsePragma.cpp
index 3204cf08ec..380eb64997 100644
--- a/lib/Parse/ParsePragma.cpp
+++ b/lib/Parse/ParsePragma.cpp
@@ -1057,20 +1057,23 @@ bool Parser::HandlePragmaLoopHint(LoopHint &Hint) {
   bool OptionUnroll = false;
   bool OptionUnrollAndJam = false;
   bool OptionDistribute = false;
+  bool OptionPipelineDisabled = false;
   bool StateOption = false;
   if (OptionInfo) { // Pragma Unroll does not specify an option.
     OptionUnroll = OptionInfo->isStr("unroll");
     OptionUnrollAndJam = OptionInfo->isStr("unroll_and_jam");
     OptionDistribute = OptionInfo->isStr("distribute");
+    OptionPipelineDisabled = OptionInfo->isStr("pipeline");
     StateOption = llvm::StringSwitch<bool>(OptionInfo->getName())
                       .Case("vectorize", true)
                       .Case("interleave", true)
                       .Default(false) ||
-                  OptionUnroll || OptionUnrollAndJam || OptionDistribute;
+                  OptionUnroll || OptionUnrollAndJam || OptionDistribute ||
+                  OptionPipelineDisabled;
   }
 
-  bool AssumeSafetyArg =
-      !OptionUnroll && !OptionUnrollAndJam && !OptionDistribute;
+  bool AssumeSafetyArg = !OptionUnroll && !OptionUnrollAndJam &&
+                         !OptionDistribute && !OptionPipelineDisabled;
   // Verify loop hint has an argument.
   if (Toks[0].is(tok::eof)) {
     ConsumeAnnotationToken();
@@ -1087,16 +1090,21 @@ bool Parser::HandlePragmaLoopHint(LoopHint &Hint) {
     SourceLocation StateLoc = Toks[0].getLocation();
     IdentifierInfo *StateInfo = Toks[0].getIdentifierInfo();
 
-    bool Valid =
-        StateInfo && llvm::StringSwitch<bool>(StateInfo->getName())
-                         .Cases("enable", "disable", true)
-                         .Case("full", OptionUnroll || OptionUnrollAndJam)
-                         .Case("assume_safety", AssumeSafetyArg)
-                         .Default(false);
+    bool Valid = StateInfo &&
+                 llvm::StringSwitch<bool>(StateInfo->getName())
+                     .Case("disable", true)
+                     .Case("enable", !OptionPipelineDisabled)
+                     .Case("full", OptionUnroll || OptionUnrollAndJam)
+                     .Case("assume_safety", AssumeSafetyArg)
+                     .Default(false);
     if (!Valid) {
-      Diag(Toks[0].getLocation(), diag::err_pragma_invalid_keyword)
-          << /*FullKeyword=*/(OptionUnroll || OptionUnrollAndJam)
-          << /*AssumeSafetyKeyword=*/AssumeSafetyArg;
+      if (OptionPipelineDisabled) {
+        Diag(Toks[0].getLocation(), diag::err_pragma_pipeline_invalid_keyword);
+      } else {
+        Diag(Toks[0].getLocation(), diag::err_pragma_invalid_keyword)
+            << /*FullKeyword=*/(OptionUnroll || OptionUnrollAndJam)
+            << /*AssumeSafetyKeyword=*/AssumeSafetyArg;
+      }
       return false;
     }
     if (Toks.size() > 2)
@@ -2810,6 +2818,8 @@ static bool ParseLoopHintValue(Preprocessor &PP, Token &Tok, Token PragmaName,
 ///    'vectorize_width' '(' loop-hint-value ')'
 ///    'interleave_count' '(' loop-hint-value ')'
 ///    'unroll_count' '(' loop-hint-value ')'
+///    'pipeline' '(' disable ')'
+///    'pipeline_initiation_interval' '(' loop-hint-value ')'
 ///
 ///  loop-hint-keyword:
 ///    'enable'
@@ -2869,6 +2879,8 @@ void PragmaLoopHintHandler::HandlePragma(Preprocessor &PP,
                            .Case("vectorize_width", true)
                            .Case("interleave_count", true)
                            .Case("unroll_count", true)
+                           .Case("pipeline", true)
+                           .Case("pipeline_initiation_interval", true)
                            .Default(false);
     if (!OptionValid) {
       PP.Diag(Tok.getLocation(), diag::err_pragma_loop_invalid_option)