[PATCH] Use MCFillFragment for zero-initialized data
Serge Pavlov
sepavloff at gmail.com
Thu Jun 27 04:47:22 PDT 2013
Updated test.
Hi rafael, grosbach,
http://llvm-reviews.chandlerc.com/D1043
CHANGE SINCE LAST DIFF
http://llvm-reviews.chandlerc.com/D1043?vs=2567&id=2594#toc
Files:
include/llvm/MC/MCObjectStreamer.h
include/llvm/MC/MCStreamer.h
lib/MC/MCAssembler.cpp
lib/MC/MCObjectStreamer.cpp
lib/MC/MCStreamer.cpp
test/MC/ELF/bss-large.ll
Index: include/llvm/MC/MCObjectStreamer.h
===================================================================
--- include/llvm/MC/MCObjectStreamer.h
+++ include/llvm/MC/MCObjectStreamer.h
@@ -116,6 +116,7 @@
virtual void EmitGPRel64Value(const MCExpr *Value);
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace = 0);
+ virtual void EmitZeros(uint64_t NumBytes, unsigned AddrSpace = 0);
virtual void FinishImpl();
/// @}
Index: include/llvm/MC/MCStreamer.h
===================================================================
--- include/llvm/MC/MCStreamer.h
+++ include/llvm/MC/MCStreamer.h
@@ -472,11 +472,9 @@
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace = 0);
- /// EmitZeros - Emit NumBytes worth of zeros. This is a convenience
- /// function that just wraps EmitFill.
- void EmitZeros(uint64_t NumBytes, unsigned AddrSpace = 0) {
- EmitFill(NumBytes, 0, AddrSpace);
- }
+ /// \brief EmitZeros - Emit NumBytes worth of zeros.
+ /// This function properly handles data in virtual sections.
+ virtual void EmitZeros(uint64_t NumBytes, unsigned AddrSpace = 0);
/// EmitValueToAlignment - Emit some number of copies of @p Value until
/// the byte alignment @p ByteAlignment is reached.
Index: lib/MC/MCAssembler.cpp
===================================================================
--- lib/MC/MCAssembler.cpp
+++ lib/MC/MCAssembler.cpp
@@ -708,12 +708,13 @@
case MCFragment::FT_Align:
// Check that we aren't trying to write a non-zero value into a virtual
// section.
- assert((!cast<MCAlignFragment>(it)->getValueSize() ||
- !cast<MCAlignFragment>(it)->getValue()) &&
+ assert((cast<MCAlignFragment>(it)->getValueSize() == 0 ||
+ cast<MCAlignFragment>(it)->getValue() == 0) &&
"Invalid align in virtual section!");
break;
case MCFragment::FT_Fill:
- assert(!cast<MCFillFragment>(it)->getValueSize() &&
+ assert((cast<MCFillFragment>(it)->getValueSize() == 0 ||
+ cast<MCFillFragment>(it)->getValue() == 0) &&
"Invalid fill in virtual section!");
break;
}
Index: lib/MC/MCObjectStreamer.cpp
===================================================================
--- lib/MC/MCObjectStreamer.cpp
+++ lib/MC/MCObjectStreamer.cpp
@@ -18,6 +18,7 @@
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
@@ -374,6 +375,12 @@
getOrCreateDataFragment()->getContents().append(NumBytes, FillValue);
}
+void MCObjectStreamer::EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
+ assert(AddrSpace == 0 && "Address space must be 0!");
+ unsigned ItemSize = getCurrentSection().first->isVirtualSection() ? 0 : 1;
+ insert(new MCFillFragment(0, ItemSize, NumBytes));
+}
+
void MCObjectStreamer::FinishImpl() {
// Dump out the dwarf file & directory tables and line tables.
const MCSymbol *LineSectionSymbol = NULL;
Index: lib/MC/MCStreamer.cpp
===================================================================
--- lib/MC/MCStreamer.cpp
+++ lib/MC/MCStreamer.cpp
@@ -154,6 +154,12 @@
EmitValue(E, 1, AddrSpace);
}
+/// EmitZeros - Emit NumBytes worth of zeros. Implementation in this class
+/// just redirects to EmitFill.
+void MCStreamer::EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
+ EmitFill(NumBytes, 0, AddrSpace);
+}
+
bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
StringRef Directory,
StringRef Filename, unsigned CUID) {
Index: test/MC/ELF/bss-large.ll
===================================================================
--- /dev/null
+++ test/MC/ELF/bss-large.ll
@@ -0,0 +1,13 @@
+; RUN: llc -filetype=obj %s -o %t
+
+; PR16338 - ICE when compiling very large two-dimensional array
+; Check if a huge object can be put into bss section
+; C++ code is:
+; int a[60666][60666];
+
+; ModuleID = 'test.c'
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a0 = addrspace(1) global [4 x [4 x i32]] zeroinitializer, align 16
+ at a = global [60666 x [60666 x i32]] zeroinitializer, align 16
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