ELF does not imply GNU/Linux. Do not assume GNU conventions just because we

are targeting an ELF platform.  Only fold gs-relative (and fs-relative) loads
if it is actually sensible to do so for the target platform.

This fixes PR13438.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160687 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Chisnall 2012-07-24 20:04:16 +00:00
parent 9dc5b3e6c4
commit 23a62cbaf5
2 changed files with 21 additions and 1 deletions

View File

@ -593,7 +593,7 @@ bool X86DAGToDAGISel::MatchLoadInAddress(LoadSDNode *N, X86ISelAddressMode &AM){
// For more information see http://people.redhat.com/drepper/tls.pdf
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Address))
if (C->getSExtValue() == 0 && AM.Segment.getNode() == 0 &&
Subtarget->isTargetELF())
Subtarget->isTargetLinux())
switch (N->getPointerInfo().getAddrSpace()) {
case 256:
AM.Segment = CurDAG->getRegister(X86::GS, MVT::i16);

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@ -0,0 +1,20 @@
; RUN: llc < %s -mtriple=x86_64-unknown-freebsd | FileCheck %s --check-prefix=CHECK-FBSD
; RUN: llc < %s -mtriple=x86_64-unknown-linux | FileCheck %s --check-prefix=CHECK-LINUX
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
%struct.thread = type { i32, i32, i32, i32 }
define i32 @test() nounwind uwtable {
entry:
%0 = load volatile %struct.thread* addrspace(256)* null
%c = getelementptr inbounds %struct.thread* %0, i64 0, i32 2
%1 = load i32* %c, align 4
ret i32 %1
}
; Check that we are not assuming that gs contains the address of gs if we are not targeting Linux
; CHECK-FBSD: movq %gs:0, %rax
; CHECK-FBSD: movl 8(%rax), %eax
; Check that we are assuming that gs contains the address of gs if we are targeting Linux
; CHECK-LINUX: movl %gs:8, %eax