[ThinLTO] Indirect call promotion fixes for promoted local functions

Summary:
Fix a couple issues limiting the application of indirect call promotion
in ThinLTO mode:
- Invoke indirect call promotion before globalopt, since it may
  eliminate imported functions which appear unreferenced.
- Invoke indirect call promotion with InLTO=true so that the PGOFuncName
  metadata is used to get the name for locals which would have been
  renamed during promotion.

Reviewers: davidxl, mehdi_amini

Subscribers: Prazek, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24004

llvm-svn: 280024

2 files changed, 19 insertions, 3 deletions

diff --git a/llvm/test/Transforms/PGOProfile/Inputs/thinlto_indirect_call_promotion.ll b/llvm/test/Transforms/PGOProfile/Inputs/thinlto_indirect_call_promotion.ll
index c77eb5172d8..8732e540767 100644
--- a/llvm/test/Transforms/PGOProfile/Inputs/thinlto_indirect_call_promotion.ll
+++ b/llvm/test/Transforms/PGOProfile/Inputs/thinlto_indirect_call_promotion.ll
@@ -1,7 +1,16 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
+source_filename = "thinlto_indirect_call_promotion.c"
+
 define void @a() {
 entry:
   ret void
 }
+
+define internal void @c() !PGOFuncName !1 {
+entry:
+  ret void
+}
+
+!1 = !{!"thinlto_indirect_call_promotion.c:c"}
diff --git a/llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll b/llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll
index 49dc7fa39e0..01f458a90a5 100644
--- a/llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll
+++ b/llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll
@@ -4,26 +4,33 @@
 ; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
 
 ; RUN: opt -function-import -summary-file %t3.thinlto.bc %t.bc -o %t4.bc -print-imports 2>&1 | FileCheck %s --check-prefix=IMPORTS
-; IMPORTS: Import a
+; IMPORTS-DAG: Import a
+; IMPORTS-DAG: Import c
 
-; RUN: opt %t4.bc -pgo-icall-prom -S -icp-count-threshold=1 | FileCheck %s --check-prefix=ICALL-PROM
-; RUN: opt %t4.bc -pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-count-threshold=1 2>&1 | FileCheck %s --check-prefix=PASS-REMARK
+; RUN: opt %t4.bc -icp-lto -pgo-icall-prom -S -icp-count-threshold=1 | FileCheck %s --check-prefix=ICALL-PROM
+; RUN: opt %t4.bc -icp-lto -pgo-icall-prom -S -pass-remarks=pgo-icall-prom -icp-count-threshold=1 2>&1 | FileCheck %s --check-prefix=PASS-REMARK
 ; PASS-REMARK: Promote indirect call to a with count 1 out of 1
+; PASS-REMARK: Promote indirect call to c.llvm.0 with count 1 out of 1
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @foo = external local_unnamed_addr global void ()*, align 8
+@bar = external local_unnamed_addr global void ()*, align 8
 
 define i32 @main() local_unnamed_addr {
 entry:
   %0 = load void ()*, void ()** @foo, align 8
 ; ICALL-PROM:   br i1 %{{[0-9]+}}, label %if.true.direct_targ, label %if.false.orig_indirect, !prof [[BRANCH_WEIGHT:![0-9]+]]
   tail call void %0(), !prof !1
+  %1 = load void ()*, void ()** @bar, align 8
+; ICALL-PROM:   br i1 %{{[0-9]+}}, label %if.true.direct_targ1, label %if.false.orig_indirect2, !prof [[BRANCH_WEIGHT:![0-9]+]]
+  tail call void %1(), !prof !2
   ret i32 0
 }
 
 !1 = !{!"VP", i32 0, i64 1, i64 -6289574019528802036, i64 1}
+!2 = !{!"VP", i32 0, i64 1, i64 591260329866125152, i64 1}
 
 ; Should not have a VP annotation on new indirect call (check before and after
 ; branch_weights annotation).