[PATCH] D127835: [SCEV] recognize llvm.annotation intrinsic

[ChenZheng via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG2c3784cff859: [SCEV] recognize llvm.annotation intrinsic (authored by shchenz).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127835/new/

https://reviews.llvm.org/D127835

Files:
  llvm/docs/LangRef.rst
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Analysis/ScalarEvolution/annotation-intrinsics.ll


Index: llvm/test/Analysis/ScalarEvolution/annotation-intrinsics.ll
===================================================================
--- llvm/test/Analysis/ScalarEvolution/annotation-intrinsics.ll
+++ llvm/test/Analysis/ScalarEvolution/annotation-intrinsics.ll
@@ -8,7 +8,7 @@
 ; CHECK-LABEL: 'annotation'
 ; CHECK-NEXT:  Classifying expressions for: @annotation
 ; CHECK-NEXT:    %1 = tail call i64 @llvm.annotation.i64(i64 %x, i8* null, i8* null, i32 0)
-; CHECK-NEXT:    --> %1 U: full-set S: full-set
+; CHECK-NEXT:    --> %x U: full-set S: full-set
 ; CHECK-NEXT:  Determining loop execution counts for: @annotation
 ;
   %1 = tail call i64 @llvm.annotation.i64(i64 %x, i8* null, i8* null, i32 0)
@@ -19,7 +19,7 @@
 ; CHECK-LABEL: 'ptr_annotation'
 ; CHECK-NEXT:  Classifying expressions for: @ptr_annotation
 ; CHECK-NEXT:    %1 = call i8* @llvm.ptr.annotation.p0i8(i8* %x, i8* null, i8* null, i32 0, i8* null)
-; CHECK-NEXT:    --> %1 U: full-set S: full-set
+; CHECK-NEXT:    --> %x U: full-set S: full-set
 ; CHECK-NEXT:  Determining loop execution counts for: @ptr_annotation
 ;
   %1 = call i8* @llvm.ptr.annotation.p0i8(i8* %x, i8* null, i8* null, i32 0, i8* null)
Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -7365,6 +7365,8 @@
         Ops.push_back(II->getArgOperand(1));
         return nullptr;
       case Intrinsic::start_loop_iterations:
+      case Intrinsic::annotation:
+      case Intrinsic::ptr_annotation:
         Ops.push_back(II->getArgOperand(0));
         return nullptr;
       default:
@@ -7816,8 +7818,10 @@
         return getAddExpr(ClampedX, Y, SCEV::FlagNUW);
       }
       case Intrinsic::start_loop_iterations:
-        // A start_loop_iterations is just equivalent to the first operand for
-        // SCEV purposes.
+      case Intrinsic::annotation:
+      case Intrinsic::ptr_annotation:
+        // A start_loop_iterations or llvm.annotation or llvm.prt.annotation is
+        // just eqivalent to the first operand for SCEV purposes.
         return getSCEV(II->getArgOperand(0));
       default:
         break;
Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -23575,8 +23575,10 @@
 
 This intrinsic allows annotation of a pointer to an integer with arbitrary
 strings. This can be useful for special purpose optimizations that want to look
-for these annotations. These have no other defined use; they are ignored by code
-generation and optimization.
+for these annotations. These have no other defined use; transformations preserve
+annotations on a best-effort basis but are allowed to replace the intrinsic with
+its first argument without breaking semantics and the intrinsic is completely
+dropped during instruction selection.
 
 '``llvm.annotation.*``' Intrinsic
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -23611,10 +23613,12 @@
 Semantics:
 """"""""""
 
-This intrinsic allows annotations to be put on arbitrary expressions
-with arbitrary strings. This can be useful for special purpose
-optimizations that want to look for these annotations. These have no
-other defined use; they are ignored by code generation and optimization.
+This intrinsic allows annotations to be put on arbitrary expressions with
+arbitrary strings. This can be useful for special purpose optimizations that
+want to look for these annotations. These have no other defined use;
+transformations preserve annotations on a best-effort basis but are allowed to
+replace the intrinsic with its first argument without breaking semantics and the
+intrinsic is completely dropped during instruction selection.
 
 '``llvm.codeview.annotation``' Intrinsic
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D127835.441994.patch
Type: text/x-patch
Size: 3881 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220704/c87b660c/attachment-0001.bin>