[llvm-commits] [llvm] r145890 - in /llvm/trunk: lib/Target/ARM/ARMAsmPrinter.cpp lib/Target/ARM/ARMConstantIslandPass.cpp test/CodeGen/ARM/globals.ll

[Jakob Stoklund Olesen]

Author: stoklund
Date: Mon Dec  5 19:43:02 2011
New Revision: 145890

URL: http://llvm.org/viewvc/llvm-project?rev=145890&view=rev
Log:
Align ARM constant pool islands via their basic block.

Previously, all ARM::CONSTPOOL_ENTRY instructions had a hardwired
alignment of 4 bytes emitted by ARMAsmPrinter.  Now the same alignment
is set on the basic block.

This is in preparation of supporting ARM constant pool islands with
different alignments.

Modified:
    llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
    llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp
    llvm/trunk/test/CodeGen/ARM/globals.ll

Modified: llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp?rev=145890&r1=145889&r2=145890&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp Mon Dec  5 19:43:02 2011
@@ -1481,11 +1481,10 @@
     /// in the function.  The first operand is the ID# for this instruction, the
     /// second is the index into the MachineConstantPool that this is, the third
     /// is the size in bytes of this constant pool entry.
+    /// The required alignment is specified on the basic block holding this MI.
     unsigned LabelId = (unsigned)MI->getOperand(0).getImm();
     unsigned CPIdx   = (unsigned)MI->getOperand(1).getIndex();
 
-    EmitAlignment(2);
-
     // Mark the constant pool entry as data if we're not already in a data
     // region.
     OutStreamer.EmitDataRegion();

Modified: llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp?rev=145890&r1=145889&r2=145890&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMConstantIslandPass.cpp Mon Dec  5 19:43:02 2011
@@ -398,6 +398,9 @@
   MachineBasicBlock *BB = MF.CreateMachineBasicBlock();
   MF.push_back(BB);
 
+  // Mark the basic block as 4-byte aligned as required by the const-pool.
+  BB->setAlignment(2);
+
   // Add all of the constants from the constant pool to the end block, use an
   // identity mapping of CPI's to CPE's.
   const std::vector<MachineConstantPoolEntry> &CPs =
@@ -1311,6 +1314,9 @@
   CPEntries[CPI].push_back(CPEntry(U.CPEMI, ID, 1));
   ++NumCPEs;
 
+  // Mark the basic block as 4-byte aligned as required by the const-pool entry.
+  NewIsland->setAlignment(2);
+
   BBOffsets[NewIsland->getNumber()] = BBOffsets[NewMBB->getNumber()];
   // Compensate for .align 2 in thumb mode.
   if (isThumb && (BBOffsets[NewIsland->getNumber()]%4 != 0 || HasInlineAsm))

Modified: llvm/trunk/test/CodeGen/ARM/globals.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/globals.ll?rev=145890&r1=145889&r2=145890&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/globals.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/globals.ll Mon Dec  5 19:43:02 2011
@@ -70,6 +70,5 @@
 ; LinuxPIC: .align 2
 ; LinuxPIC: .LCPI0_0:
 ; LinuxPIC:     .long _GLOBAL_OFFSET_TABLE_-(.LPC0_0+8)
-; LinuxPIC: .align 2
 ; LinuxPIC: .LCPI0_1:
 ; LinuxPIC:     .long	G(GOT)