[llvm-commits] [llvm] r140355 - in /llvm/trunk: lib/Target/X86/X86FastISel.cpp test/CodeGen/X86/fast-isel-tls.ll

[Eli Friedman]

Author: efriedma
Date: Thu Sep 22 18:41:28 2011
New Revision: 140355

URL: http://llvm.org/viewvc/llvm-project?rev=140355&view=rev
Log:
PR10991: make fast-isel correctly check whether accessing a global through an alias involves thread-local storage.  (I'm not entirely sure how this is supposed to work, but this patch makes fast-isel consistent with the normal isel path.)


Modified:
    llvm/trunk/lib/Target/X86/X86FastISel.cpp
    llvm/trunk/test/CodeGen/X86/fast-isel-tls.ll

Modified: llvm/trunk/lib/Target/X86/X86FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FastISel.cpp?rev=140355&r1=140354&r2=140355&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FastISel.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FastISel.cpp Thu Sep 22 18:41:28 2011
@@ -22,6 +22,7 @@
 #include "llvm/CallingConv.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/GlobalVariable.h"
+#include "llvm/GlobalAlias.h"
 #include "llvm/Instructions.h"
 #include "llvm/IntrinsicInst.h"
 #include "llvm/Operator.h"
@@ -467,14 +468,23 @@
 
   // Handle constant address.
   if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
-    // Can't handle alternate code models or TLS yet.
+    // Can't handle alternate code models yet.
     if (TM.getCodeModel() != CodeModel::Small)
       return false;
 
+    // Can't handle TLS yet.
     if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
       if (GVar->isThreadLocal())
         return false;
 
+    // Can't handle TLS yet, part 2 (this is slightly crazy, but this is how
+    // it works...).
+    if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
+      if (const GlobalVariable *GVar =
+            dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal(false)))
+        if (GVar->isThreadLocal())
+          return false;
+
     // RIP-relative addresses can't have additional register operands, so if
     // we've already folded stuff into the addressing mode, just force the
     // global value into its own register, which we can use as the basereg.

Modified: llvm/trunk/test/CodeGen/X86/fast-isel-tls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fast-isel-tls.ll?rev=140355&r1=140354&r2=140355&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fast-isel-tls.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fast-isel-tls.ll Thu Sep 22 18:41:28 2011
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=x86 -relocation-model=pic -mtriple=i686-unknown-linux-gnu -fast-isel | grep __tls_get_addr
+; RUN: llc < %s -march=x86 -relocation-model=pic -mtriple=i686-unknown-linux-gnu -fast-isel | FileCheck %s
 ; PR3654
 
 @v = thread_local global i32 0
@@ -8,3 +8,19 @@
           %s = add i32 %t, 1
           ret i32 %s
 }
+
+; CHECK: f:
+; CHECK: leal	v at TLSGD
+; CHECK: __tls_get_addr
+
+ at alias = alias internal i32* @v
+define i32 @f_alias() nounwind {
+entry:
+          %t = load i32* @v
+          %s = add i32 %t, 1
+          ret i32 %s
+}
+
+; CHECK: f_alias:
+; CHECK: leal	v at TLSGD
+; CHECK: __tls_get_addr