Commit 69794107 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r338599: 

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r338599 | vlad.tsyrklevich | 2018-08-01 19:44:37 +0200 (Wed, 01 Aug 2018) | 16 lines

[X86] FastISel fall back on !absolute_symbol GVs

Summary:
D25878, which added support for !absolute_symbol for normal X86 ISel,
did not add support for materializing references to absolute symbols for
X86 FastISel. This causes build failures because FastISel generates
PC-relative relocations for absolute symbols. Fall back to normal ISel
for references to !absolute_symbol GVs. Fix for PR38200.

Reviewers: pcc, craig.topper

Reviewed By: pcc

Subscribers: hiraditya, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D50116
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llvm-svn: 338847
parent 6d8abb07

llvm/lib/Target/X86/X86FastISel.cpp

+4 −0
Original line number Diff line number Diff line
@@ -738,6 +738,10 @@ bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) { 
    if (GV->isThreadLocal())

      return false;



    // Can't handle !absolute_symbol references yet.

    if (GV->isAbsoluteSymbolRef())

      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.

llvm/test/CodeGen/X86/absolute-bit-mask-fastisel.ll

0 → 100644
+28 −0
Original line number Diff line number Diff line 
; RUN: llc < %s | FileCheck %s

; RUN: llc -relocation-model=pic < %s | FileCheck %s



; Regression test for PR38200



target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

target triple = "x86_64-unknown-linux-gnu"



@bit_mask8 = external hidden global i8, !absolute_symbol !0



declare void @f()



define void @foo8(i8* %ptr) noinline optnone {

  %load = load i8, i8* %ptr

  ; CHECK: movl $bit_mask8, %ecx

  %and = and i8 %load, ptrtoint (i8* @bit_mask8 to i8)

  %icmp = icmp eq i8 %and, 0

  br i1 %icmp, label %t, label %f



t:

  call void @f()

  ret void



f:

  ret void

}



!0 = !{i64 0, i64 256}