[PATCH] D13481: [X86] Call locally defined function directly for PIE

[H.J Lu via llvm-commits]

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There is no need to use PLT to call locally defined function for PIE
since locally defined function in PIE can't be preempted.

Fixes PR 24970.

Repository:
  rL LLVM

http://reviews.llvm.org/D13481

Files:
  lib/Target/X86/X86FastISel.cpp
  lib/Target/X86/X86ISelLowering.cpp
  test/CodeGen/X86/pie-1.ll
  test/CodeGen/X86/pie-2.ll

Index: test/CodeGen/X86/pie-2.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/pie-2.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s -mcpu=generic -mtriple=i686-linux-gnu -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=i686-linux-gnu -fast-isel -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux-gnu -fast-isel -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+
+; LINUX:	call{{l|q}}	foo
+
+ at glob = common global i32 0, align 4
+
+; Function Attrs: nounwind uwtable
+define i32 @foo() {
+entry:
+  %0 = load i32, i32* @glob, align 4
+  ret i32 %0
+}
+
+; Function Attrs: nounwind uwtable
+define void @bar() {
+entry:
+  %call = call i32 @foo()
+  store i32 %call, i32* @glob, align 4
+  ret void
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"PIC Level", i32 2}
Index: test/CodeGen/X86/pie-1.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/pie-1.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s -mcpu=generic -mtriple=i686-linux-gnu -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=i686-linux-gnu -fast-isel -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux-gnu -fast-isel -relocation-model=pic -asm-verbose=false -enable-pie | FileCheck %s -check-prefix=LINUX
+
+; LINUX-NOT:	call{{l|q}}	foo at PLT
+
+ at glob = common global i32 0, align 4
+
+; Function Attrs: nounwind uwtable
+define i32 @foo() {
+entry:
+  %0 = load i32, i32* @glob, align 4
+  ret i32 %0
+}
+
+; Function Attrs: nounwind uwtable
+define void @bar() {
+entry:
+  %call = call i32 @foo()
+  store i32 %call, i32* @glob, align 4
+  ret void
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"PIC Level", i32 2}
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -3304,6 +3304,8 @@
       // we don't need to use the PLT - we can directly call it.
       if (Subtarget->isTargetELF() &&
           DAG.getTarget().getRelocationModel() == Reloc::PIC_ &&
+          !(DAG.getTarget().Options.PositionIndependentExecutable &&
+            GV->isStrongDefinitionForLinker()) &&
           GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
         OpFlags = X86II::MO_PLT;
       } else if (Subtarget->isPICStyleStubAny() &&
Index: lib/Target/X86/X86FastISel.cpp
===================================================================
--- lib/Target/X86/X86FastISel.cpp
+++ lib/Target/X86/X86FastISel.cpp
@@ -3088,6 +3088,8 @@
     // we don't need to use the PLT - we can directly call it.
     if (Subtarget->isTargetELF() &&
         TM.getRelocationModel() == Reloc::PIC_ &&
+        !(TM.Options.PositionIndependentExecutable &&
+          GV->isStrongDefinitionForLinker()) &&
         GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
       OpFlags = X86II::MO_PLT;
     } else if (Subtarget->isPICStyleStubAny() &&


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