[llvm] r349800 - [MC] [AArch64] Correctly resolve ":abs_g1:3" etc.

[Eli Friedman via llvm-commits]

Author: efriedma
Date: Thu Dec 20 11:46:14 2018
New Revision: 349800

URL: http://llvm.org/viewvc/llvm-project?rev=349800&view=rev
Log:
[MC] [AArch64] Correctly resolve ":abs_g1:3" etc.

We have to treat constructs like this as if they were "symbolic", to use
the correct codepath to resolve them.  This mostly only affects movz
etc. because the other uses of classifySymbolRef conservatively treat
everything that isn't a constant as if it were a symbol.

Differential Revision: https://reviews.llvm.org/D55906


Modified:
    llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
    llvm/trunk/test/MC/AArch64/fixup-absolute.s

Modified: llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp?rev=349800&r1=349799&r2=349800&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp Thu Dec 20 11:46:14 2018
@@ -5434,10 +5434,16 @@ AArch64AsmParser::classifySymbolRef(cons
   // Check that it looks like a symbol + an addend
   MCValue Res;
   bool Relocatable = Expr->evaluateAsRelocatable(Res, nullptr, nullptr);
-  if (!Relocatable || !Res.getSymA() || Res.getSymB())
+  if (!Relocatable || Res.getSymB())
     return false;
 
-  DarwinRefKind = Res.getSymA()->getKind();
+  // Treat expressions with an ELFRefKind (like ":abs_g1:3", or
+  // ":abs_g1:x" where x is constant) as symbolic even if there is no symbol.
+  if (!Res.getSymA() && ELFRefKind == AArch64MCExpr::VK_INVALID)
+    return false;
+
+  if (Res.getSymA())
+    DarwinRefKind = Res.getSymA()->getKind();
   Addend = Res.getConstant();
 
   // It's some symbol reference + a constant addend, but really

Modified: llvm/trunk/test/MC/AArch64/fixup-absolute.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/fixup-absolute.s?rev=349800&r1=349799&r2=349800&view=diff
==============================================================================
--- llvm/trunk/test/MC/AArch64/fixup-absolute.s (original)
+++ llvm/trunk/test/MC/AArch64/fixup-absolute.s Thu Dec 20 11:46:14 2018
@@ -1,21 +1,40 @@
 // RUN: llvm-mc -triple aarch64--none-eabi -filetype obj < %s -o - | llvm-objdump -d - | FileCheck %s
 
+onepart_before = 0x1234
+twopart_before = 0x12345678
+threepart_before = 0x1234567890AB
+fourpart_before = 0x1234567890ABCDEF
+
+// CHECK: mov     x0, #1311673391471656960
 // CHECK: mov     x0, #1311673391471656960
-movz x0, #:abs_g3:fourpart
+movz x0, #:abs_g3:fourpart_before
+movz x0, #:abs_g3:fourpart_after
 // CHECK: mov     x0, #20014547599360
-movz x0, #:abs_g2:threepart
+// CHECK: mov     x0, #20014547599360
+movz x0, #:abs_g2:threepart_before
+movz x0, #:abs_g2:threepart_after
+// CHECK: movk    x0, #22136, lsl #32
 // CHECK: movk    x0, #22136, lsl #32
-movk x0, #:abs_g2_nc:fourpart
+movk x0, #:abs_g2_nc:fourpart_before
+movk x0, #:abs_g2_nc:fourpart_after
 // CHECK: mov     x0, #305397760
-movz x0, #:abs_g1:twopart
+// CHECK: mov     x0, #305397760
+movz x0, #:abs_g1:twopart_before
+movz x0, #:abs_g1:twopart_after
+// CHECK: movk    x0, #37035, lsl #16
 // CHECK: movk    x0, #37035, lsl #16
-movk x0, #:abs_g1_nc:fourpart
+movk x0, #:abs_g1_nc:fourpart_before
+movk x0, #:abs_g1_nc:fourpart_after
 // CHECK: mov     x0, #4660
-movz x0, #:abs_g0:onepart
+// CHECK: mov     x0, #4660
+movz x0, #:abs_g0:onepart_before
+movz x0, #:abs_g0:onepart_after
+// CHECK: movk    x0, #52719
 // CHECK: movk    x0, #52719
-movk x0, #:abs_g0_nc:fourpart
+movk x0, #:abs_g0_nc:fourpart_before
+movk x0, #:abs_g0_nc:fourpart_after
 
-onepart = 0x1234
-twopart = 0x12345678
-threepart = 0x1234567890AB
-fourpart = 0x1234567890ABCDEF
+onepart_after = 0x1234
+twopart_after = 0x12345678
+threepart_after = 0x1234567890AB
+fourpart_after = 0x1234567890ABCDEF