If we have zero initialized data with external linkage, use .zerofill to

emit it (instead of .space), saving a bit of space in the .o file.

For example:
int foo[100];
int bar[100] = {};

when compiled with C++ or -fno-common results in shrinkage from 1160 to 360
bytes of space.  The X86 backend can also do this on darwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26185 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-02-14 22:18:23 +00:00
parent ae9a84b9be
commit 0d7db6f79a

View File

@ -539,13 +539,20 @@ bool DarwinAsmPrinter::doFinalization(Module &M) {
if (C->isNullValue() && /* FIXME: Verify correct */
(I->hasInternalLinkage() || I->hasWeakLinkage() ||
I->hasLinkOnceLinkage())) {
SwitchSection(".data", I);
I->hasLinkOnceLinkage() ||
(I->hasExternalLinkage() && !I->hasSection()))) {
if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
if (I->hasInternalLinkage())
if (I->hasExternalLinkage()) {
O << "\t.globl " << name << '\n';
O << "\t.zerofill __DATA, __common, " << name << ", "
<< Size << ", " << Align;
} else if (I->hasInternalLinkage()) {
SwitchSection(".data", I);
O << LCOMMDirective << name << "," << Size << "," << Align;
else
} else {
SwitchSection(".data", I);
O << ".comm " << name << "," << Size;
}
O << "\t\t; '" << I->getName() << "'\n";
} else {
switch (I->getLinkage()) {