[LTO][codegen] Add TargetLibraryInfoWrapperPass initially

Many codegen pass require this pass with useful triple info. Legacy pass manager need to
add a TargetLibraryInfo with the module info before run passes. Or the TargetLibraryInfo
will be initialized too conservative.

Reviewed By: pengfei, aeubanks

Differential Revision: https://reviews.llvm.org/D115850

diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 855d0fc..308c602 100644 (file)
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -415,6 +415,8 @@ static void codegen(const Config &Conf, TargetMachine *TM,
   TM->Options.ObjectFilenameForDebug = Stream->ObjectPathName;
 
   legacy::PassManager CodeGenPasses;
+  TargetLibraryInfoImpl TLII(Triple(Mod.getTargetTriple()));
+  CodeGenPasses.add(new TargetLibraryInfoWrapperPass(TLII));
   CodeGenPasses.add(
       createImmutableModuleSummaryIndexWrapperPass(&CombinedIndex));
   if (Conf.PreCodeGenPassesHook)

diff --git a/llvm/test/LTO/X86/tli-sqrtf_finite.ll b/llvm/test/LTO/X86/tli-sqrtf_finite.ll
new file mode 100644 (file)
index 0000000..2d6c683
--- /dev/null
+++ b/llvm/test/LTO/X86/tli-sqrtf_finite.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s > %t
+; RUN: llvm-lto %t -exported-symbol=foo -filetype=asm -o - | FileCheck %s
+
+; Check that sqrtf_finite is recognized as a libcall by SelectionDAGBuilder
+; to enable sqrtss instruction to be used.
+
+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"
+
+define float @foo(float %x) {
+; CHECK: sqrtss
+  %call = tail call nnan ninf float @__sqrtf_finite(float %x) readnone
+  ret float %call
+}
+
+declare float @__sqrtf_finite(float) readnone