[llvm] r340761 - [PowerPC][MC] Support expressions in getMemRIX16Encoding.

[Sean Fertile via llvm-commits]

Author: sfertile
Date: Mon Aug 27 10:37:43 2018
New Revision: 340761

URL: http://llvm.org/viewvc/llvm-project?rev=340761&view=rev
Log:
[PowerPC][MC] Support expressions in getMemRIX16Encoding.

Loosens an assert in getMemRIX16Encoding that restricts DQ-form instructions to
using an immediate, so that we can assemble instructions like lxv/stxv where the
offset is an expression.

Differential Revision: https://reviews.llvm.org/D51122

Added:
    llvm/trunk/test/MC/PowerPC/ppc64-dq-expr.s
Modified:
    llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp

Modified: llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp?rev=340761&r1=340760&r2=340761&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp Mon Aug 27 10:37:43 2018
@@ -264,10 +264,16 @@ unsigned PPCMCCodeEmitter::getMemRIX16En
   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 12;
 
   const MCOperand &MO = MI.getOperand(OpNo);
-  assert(MO.isImm() && !(MO.getImm() % 16) &&
-         "Expecting an immediate that is a multiple of 16");
+  if (MO.isImm()) {
+    assert(!(MO.getImm() % 16) &&
+           "Expecting an immediate that is a multiple of 16");
+    return ((getMachineOpValue(MI, MO, Fixups, STI) >> 4) & 0xFFF) | RegBits;
+  }
 
-  return ((getMachineOpValue(MI, MO, Fixups, STI) >> 4) & 0xFFF) | RegBits;
+  // Otherwise add a fixup for the displacement field.
+  Fixups.push_back(MCFixup::create(IsLittleEndian? 0 : 2, MO.getExpr(),
+                                   (MCFixupKind)PPC::fixup_ppc_half16ds));
+  return RegBits;
 }
 
 unsigned PPCMCCodeEmitter::getSPE8DisEncoding(const MCInst &MI, unsigned OpNo,

Added: llvm/trunk/test/MC/PowerPC/ppc64-dq-expr.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/PowerPC/ppc64-dq-expr.s?rev=340761&view=auto
==============================================================================
--- llvm/trunk/test/MC/PowerPC/ppc64-dq-expr.s (added)
+++ llvm/trunk/test/MC/PowerPC/ppc64-dq-expr.s Mon Aug 27 10:37:43 2018
@@ -0,0 +1,38 @@
+# RUN: llvm-mc -triple powerpc64le-unknown-linux-gnu %s -filetype=obj -o - | \
+# RUN:    llvm-objdump -D  -r - | FileCheck %s
+        .text
+        .abiversion 2
+        .global test
+        .p2align 4
+        .type test, at function
+test:
+.Lgep:
+        addis 2, 12, .TOC.-.Lgep at ha
+        addi  2,  2, .TOC.-.Lgep at l
+.Llep:
+        .localentry  test, .Llep-.Lgep
+        addis 3, 2, vecA at toc@ha
+        lxv   3,    vecA at toc@l(3)
+        addis 3, 2, vecB at toc@ha
+        stxv  3,    vecB at toc@l(3)
+        blr
+
+        .comm  vecA, 16, 16
+        .comm  vecB, 16, 16
+
+# CHECK: Disassembly of section .text:
+# CHECK-LABEL: test:
+# CHECK-NEXT:    addis 2, 12, 0
+# CHECK-NEXT:    R_PPC64_REL16_HA     .TOC.
+# CHECK-NEXT:    addi 2, 2, 0
+# CHECK-NEXT:    R_PPC64_REL16_LO     .TOC.
+# CHECK-NEXT:    addis 3, 2, 0
+# CHECK-NEXT:    R_PPC64_TOC16_HA     vecA
+# CHECK-NEXT:    lxv 3, 0(3)
+# CHECK-NEXT:    R_PPC64_TOC16_LO_DS  vecA
+# CHECK-NEXT:    addis 3, 2, 0
+# CHECK-NEXT:    R_PPC64_TOC16_HA     vecB
+# CHECK-NEXT:    stxv 3, 0(3)
+# CHECK-NEXT:    R_PPC64_TOC16_LO_DS  vecB
+# CHECK-NEXT:    blr
+