[mips][ias] Make section sizes a multiple of the alignment.

[dsanders]

ping

[sdardis]

LGTM.

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

void MipsTargetELFStreamer::finish() {
   MCA.registerSection(DataSection);
   MCSection &BSSSection = *OFI.getBSSSection();
   MCA.registerSection(BSSSection);
 
   TextSection.setAlignment(std::max(16u, TextSection.getAlignment()));
   DataSection.setAlignment(std::max(16u, DataSection.getAlignment()));
   BSSSection.setAlignment(std::max(16u, BSSSection.getAlignment()));
 
+  // Make sections sizes a multiple of the alignment.
+  MCStreamer &OS = getStreamer();
+  for (MCSection &S : MCA) {
+    MCSectionELF &Section = static_cast<MCSectionELF &>(S);
+
+    unsigned Alignment = Section.getAlignment();
+    if (Alignment) {
+      OS.SwitchSection(&Section);
+      if (Section.UseCodeAlign())
+        OS.EmitCodeAlignment(Alignment, Alignment);
+      else
+        OS.EmitValueToAlignment(Alignment, 0, 1, Alignment);
+    }
+  }
+
   const FeatureBitset &Features = STI.getFeatureBits();
 
   // Update e_header flags. See the FIXME and comment above in
   // the constructor for a full rundown on this.
   unsigned EFlags = MCA.getELFHeaderEFlags();
 
   // ABI
   // N64 does not require any ABI bits.

test/DebugInfo/Mips/delay-slot.ll

 ; CHECK: ------------------ ------ ------ ------ --- ------------- -------------
 ; CHECK: 0x0000000000000000      1      0      1   0             0  is_stmt
 ; FIXME: The next address probably ought to be 0x0000000000000004 but there's
 ;        a constant initialization before the prologue's end.
 ; CHECK: 0x0000000000000008      2      0      1   0             0  is_stmt prologue_end
 ; CHECK: 0x000000000000002c      3      0      1   0             0  is_stmt
 ; CHECK: 0x000000000000003c      4      0      1   0             0  is_stmt
 ; CHECK: 0x0000000000000048      5      0      1   0             0  is_stmt
-; CHECK: 0x0000000000000058      5      0      1   0             0  is_stmt end_sequence
+; CHECK: 0x0000000000000060      5      0      1   0             0  is_stmt end_sequence
 
 
 target datalayout = "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64"
 target triple = "mips--linux-gnu"
 
 ; Function Attrs: nounwind
 define i32 @foo(i32 %x) #0 !dbg !4 {
 entry:

test/MC/Mips/section-size.s

+# RUN: llvm-mc -triple mips-unknown-linux -filetype=obj %s | \
+# RUN:     llvm-readobj -sections | FileCheck %s
+  .section ".talign1", "ax"
+  .p2align 4
+t1: .byte 1
+
+  .section ".talign2", "ax"
+  .p2align 3
+t2: addiu $2, $2, 1
+  addiu $2, $2, 1
+
+  .section ".talign3", "ax"
+  .p2align 3
+t3: addiu $2, $2, 1
+
+  .section ".talign4", "ax"
+t4: .byte 1
+
+  .section ".dalign1", "a"
+  .p2align 4
+d1: .byte 1
+
+  .section ".dalign2", "a"
+  .p2align 3
+d2: .word 1
+        .word 2
+
+  .section ".dalign3", "a"
+  .p2align 3
+d3: .word 1
+
+  .section ".dalign4", "a"
+d4: .byte 1
+
+  .section ".dalign5", "a"
+  .p2align 16
+d5: .word 1
+
+  .section ".nalign1", ""
+  .p2align 4
+n1: .byte 1
+
+  .section ".nalign2", ""
+  .p2align 3
+n2: .word 1
+        .word 2
+
+  .section ".nalign3", ""
+  .p2align 3
+n3: .word 1
+
+  .section ".nalign4", ""
+n4: .byte 1
+
+# CHECK-LABEL:   Name: .talign1
+# CHECK:         Size: 16
+# CHECK:         AddressAlignment: 16
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .talign2
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .talign3
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .talign4
+# CHECK:         Size: 1
+# CHECK:         AddressAlignment: 1
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .dalign1
+# CHECK:         Size: 16
+# CHECK:         AddressAlignment: 16
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .dalign2
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .dalign3
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .dalign4
+# CHECK:         Size: 1
+# CHECK:         AddressAlignment: 1
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .dalign5
+# CHECK:         Size: 65536
+# CHECK:         AddressAlignment: 65536
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .nalign1
+# CHECK:         Size: 16
+# CHECK:         AddressAlignment: 16
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .nalign2
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .nalign3
+# CHECK:         Size: 8
+# CHECK:         AddressAlignment: 8
+# CHECK-LABEL: }
+# CHECK-LABEL:   Name: .nalign4
+# CHECK:         Size: 1
+# CHECK:         AddressAlignment: 1
+# CHECK-LABEL: }