Author: Aiden Grossman
Date: 2026-07-10T09:39:17-07:00
New Revision: ca9680d281f48c7f561d49adf4923ea226f55ae4

URL: 
https://github.com/llvm/llvm-project/commit/ca9680d281f48c7f561d49adf4923ea226f55ae4
DIFF: 
https://github.com/llvm/llvm-project/commit/ca9680d281f48c7f561d49adf4923ea226f55ae4.diff

LOG: Revert "Revert "[PGO][ICP] Prevent indirect call promotion to functions 
with …"

This reverts commit 9ff1d7a21e6d23088eb5dac38f95edd4329c50b7.

Added: 
    llvm/test/Transforms/SampleProfile/icp_target_feature.ll

Modified: 
    llvm/lib/Transforms/Utils/CallPromotionUtils.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp 
b/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp
index 6912338ce5ffd..9656d99f6d473 100644
--- a/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp
+++ b/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp
@@ -477,6 +477,27 @@ bool llvm::isLegalToPromote(const CallBase &CB, Function 
*Callee,
     }
   }
 
+  // Check target feature compatibility. This is also needed to avoid incorrect
+  // inlining if the callee has the always_inline attribute. An always_inline
+  // function can be incorrectly inlined via two paths: either it is directly
+  // called and inlined, or it is indirectly called, promoted, and then 
inlined.
+  // The check here only prevents the latter case.
+  auto CalleeFeatures =
+      Callee->getFnAttribute("target-features").getValueAsString();
+  auto CallerFeatures =
+      CB.getCaller()->getFnAttribute("target-features").getValueAsString();
+  SmallVector<StringRef, 8> CalleeFeats;
+  CalleeFeatures.split(CalleeFeats, ',');
+  for (auto Feat : CalleeFeats) {
+    if (Feat.starts_with("+")) {
+      if (!CallerFeatures.contains(Feat)) {
+        if (FailureReason)
+          *FailureReason = "Incompatible target features";
+        return false;
+      }
+    }
+  }
+
   return true;
 }
 

diff  --git a/llvm/test/Transforms/SampleProfile/icp_target_feature.ll 
b/llvm/test/Transforms/SampleProfile/icp_target_feature.ll
new file mode 100644
index 0000000000000..1210a97e98b09
--- /dev/null
+++ b/llvm/test/Transforms/SampleProfile/icp_target_feature.ll
@@ -0,0 +1,61 @@
+; This test verifies that indirect call promotion (ICP) under sample profiling
+; correctly checks target feature compatibility. Specifically, a callee with
+; target features incompatible with the caller's features (e.g., "_Z3moov" 
requiring
+; "+avx512f" while caller "_Z3goov" does not support it) should not be 
promoted,
+; while a compatible callee (e.g., "_Z3hoov") should be promoted successfully.
+; Note that under Sample PGO, the promotion candidates (e.g., _Z3hoov and 
_Z3moov)
+; are retrieved directly from the sample profile file 
(Inputs/norepeated-icp-2.prof)
+; at the corresponding line offset (1) rather than using value profile !prof 
metadata.
+; RUN: opt < %s -passes=sample-profile 
-sample-profile-file=%S/Inputs/norepeated-icp-2.prof -S | FileCheck %s
+
+target datalayout = 
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@p = dso_local global ptr null, align 8
+
+; Function Attrs: uwtable mustprogress
+define dso_local void @_Z3moov() #0 !dbg !7 {
+entry:
+  ret void
+}
+
+; Function Attrs: uwtable mustprogress
+define dso_local void @_Z3hoov() #1 !dbg !11 {
+entry:
+  store ptr @_Z3moov, ptr @p, align 8
+  ret void
+}
+
+; Function Attrs: uwtable mustprogress
+define dso_local void @_Z3goov() #1 !dbg !24 {
+entry:
+  %t0 = load ptr, ptr @p, align 8
+  ; Here, _Z3moov requires "+avx512f" (attributes #0) which the caller lacks 
(attributes #1).
+  ; Therefore, _Z3moov is not promoted.
+  ; CHECK-NOT: icmp eq ptr %t0, @_Z3moov
+  ; On the other hand, _Z3hoov has compatible target features and is promoted 
successfully.
+  ; CHECK: icmp eq ptr %t0, @_Z3hoov
+  ; CHECK-NOT: icmp eq ptr %t0, @_Z3moov
+  call void %t0(), !dbg !26
+  ret void
+}
+
+attributes #0 = { uwtable mustprogress "use-sample-profile" 
"target-features"="+avx512f" }
+attributes #1 = { uwtable mustprogress "use-sample-profile" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, 
producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: 
LineTablesOnly, enums: !2, splitDebugInlining: false, debugInfoForProfiling: 
true, nameTableKind: None)
+!1 = !DIFile(filename: "1.cc", directory: "")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang"}
+!7 = distinct !DISubprogram(name: "moo", linkageName: "_Z3moov", scope: !1, 
file: !1, line: 1, type: !8, scopeLine: 1, flags: DIFlagPrototyped | 
DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: 
!0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !2)
+!11 = distinct !DISubprogram(name: "hoo", linkageName: "_Z3hoov", scope: !1, 
file: !1, line: 9, type: !8, scopeLine: 9, flags: DIFlagPrototyped | 
DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: 
!0, retainedNodes: !2)
+!24 = distinct !DISubprogram(name: "goo", linkageName: "_Z3goov", scope: !1, 
file: !1, line: 15, type: !8, scopeLine: 15, flags: DIFlagPrototyped | 
DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: 
!0, retainedNodes: !2)
+!26 = !DILocation(line: 16, column: 3, scope: !24)


        
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