[llvm-branch-commits] [llvm] bcb4361 - [NewPM] Add missing LTO ArgPromotion pass

[Tom Stellard via llvm-branch-commits]

Author: Nikita Popov
Date: 2021-09-01T17:37:57-07:00
New Revision: bcb43617cb7f124ea5c10c29818eca6f44dc5f58

URL: https://github.com/llvm/llvm-project/commit/bcb43617cb7f124ea5c10c29818eca6f44dc5f58
DIFF: https://github.com/llvm/llvm-project/commit/bcb43617cb7f124ea5c10c29818eca6f44dc5f58.diff

LOG: [NewPM] Add missing LTO ArgPromotion pass

This is a followup to D96780 to add one more pass missing from the
NewPM LTO pipeline. The missing ArgPromotion run is inserted at
the same position as in the LegacyPM, resolving the already
present FIXME:
https://github.com/llvm/llvm-project/blob/16086d47c0d0cd08ffae8e69a69c88653e654d01/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp#L1096-L1098

The compile-time impact is minimal with ~0.1% geomean regression
on CTMark.

Differential Revision: https://reviews.llvm.org/D108866

(cherry picked from commit b28c3b9d9f4292d7779a0e2661d308f1230c6ecd)

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilder.cpp
    llvm/test/Other/new-pm-lto-defaults.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 79fcc8569b6d0..0bc955dbbfea3 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -1784,9 +1784,12 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   MPM.addPass(GlobalOptPass());
 
   // Garbage collect dead functions.
-  // FIXME: Add ArgumentPromotion pass after once it's ported.
   MPM.addPass(GlobalDCEPass());
 
+  // If we didn't decide to inline a function, check to see if we can
+  // transform it to pass arguments by value instead of by reference.
+  MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(ArgumentPromotionPass()));
+
   FunctionPassManager FPM;
   // The IPO Passes may leave cruft around. Clean up after them.
   FPM.addPass(InstCombinePass());

diff  --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll
index 8f1830dbc610d..9a00f1931bff5 100644
--- a/llvm/test/Other/new-pm-lto-defaults.ll
+++ b/llvm/test/Other/new-pm-lto-defaults.ll
@@ -73,6 +73,7 @@
 ; CHECK-O23SZ-NEXT: Running pass: InlinerPass
 ; CHECK-O23SZ-NEXT: Running pass: GlobalOptPass
 ; CHECK-O23SZ-NEXT: Running pass: GlobalDCEPass
+; CHECK-O23SZ-NEXT: Running pass: ArgumentPromotionPass
 ; CHECK-O23SZ-NEXT: Running pass: InstCombinePass
 ; CHECK-EP-Peephole-NEXT: Running pass: NoOpFunctionPass
 ; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass