Fix the code that was WRONG.

The registers are placed into the saved registers list in the reverse order,
which is why the original loop was written to loop backwards.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148064 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2012-01-12 23:05:03 +00:00
parent d578b905de
commit 86b1a7d614
3 changed files with 208 additions and 13 deletions

View File

@ -106,6 +106,11 @@
<li><a href="#fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a></li>
</ol>
</li>
<li><a href="#module_flags">Module Flags Metadata</a>
<ol>
<li><a href="#objc_metadata">Objective-C Metadata</a></li>
</ol>
</li>
</ol>
</li>
<li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
@ -3024,6 +3029,138 @@ call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
</div>
</div>
<!-- ======================================================================= -->
<h3>
<a name="module_flags">Module Flags Metadata</a>
</h3>
<div>
<p>Occasionally, the front-end needs to transmit data to the linker which
affects its behavior. The LLVM IR isn't sufficient to transmit this
information, so one should use the <tt>llvm.module.flags</tt> named
metadata.</p>
<p>The <tt>llvm.module.flags</tt> metadata is a named metadata, whose elements
consist of metadata triplets. For example:</p>
<pre class="doc_code">
!0 = metadata !{ i32 0, metadata !"foo", i32 1 }
!1 = metadata !{ i32 1, metadata !"bar", i32 37 }
!llvm.module.flags = !{ !0, !1 }
</pre>
<p>The first field specifies the behavior of the linker upon encountering two of
the same values. Behavior could range from: emitting an error if some of the
modules' flags disagree, emitting a warning, etc. The second field is the
name of the metadata. The third field is the value of the metadata.</p>
<p>When two modules are linked together, the <tt>llvm.module.flags</tt> metadata
are unioned together.</p>
</div>
<!-- _______________________________________________________________________ -->
<h4>
<a name="objc_metadata">Objective-C Metadata</a>
</h4>
<div>
<p>The following module flags are used to convey Objective-C metadata to the
linker.</p>
<table border="1" cellspacing="0" cellpadding="4">
<tbody>
<tr>
<th>Value</th>
<th>Behavior</th>
</tr>
<tr>
<td>1</td>
<td align="left">
<dl>
<dt><tt>Error</tt></dt>
<dd>Causes the linker to emit an error when two values disagree.</dd>
</dl>
</td>
</tr>
<tr>
<td>2</td>
<td align="left">
<dl>
<dt><tt>Require</tt></dt>
<dd>Causes the linker to emit an error when the specified value is not
present.</dd>
</dl>
</td>
</tr>
<tr>
<td>3</td>
<td align="left">
<dl>
<dt><tt>Override</tt></dt>
<dd>Causes the linker to use the specified value if the two values
disagree. It's an error if two pieces of the same metadata have
the <tt>Override</tt> behavior but different values.</dd>
</dl>
</td>
</tr>
</tbody>
</table>
<p>The names are:</p>
<ul>
<li><tt>Objective-C Version</tt></li>
<li><tt>Objective-C Garbage Collection</tt></li>
<li><tt>Objective-C GC Only</tt></li>
<li><tt>Objective-C Image Info Section</tt></li>
</ul>
<p>
<p>Here is an example of how to use the Objective-C metadata:</p>
<pre class="doc_code">
<u>Module A</u>
!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
!1 = metadata !{ i32 1, metadata !"Objective-C Garbage Collection", i32 2 }
!2 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
!llvm.module.flags = !{ !0, !1, !2 }
<u>Module B</u>
!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
!1 = metadata !{ i32 1, metadata !"Objective-C Garbage Collection", i32 2 }
!2 = metadata !{ i32 1, metadata !"Objective-C GC Only", i32 4 }
!3 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
!4 = metadata !{ i32 2, metadata !"Objective-C GC Only",
metadata !{
metadata !"Objective-C Garbage Collection", i32 2
}
}
!llvm.module.flags = !{ !0, !1, !2, !3, !4 }
<u>Linked Module</u>
!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
!1 = metadata !{ i32 3, metadata !"Objective-C Garbage Collection", i32 2 }
!2 = metadata !{ i32 1, metadata !"Objective-C GC Only", i32 4 }
!3 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
!4 = metadata !{ i32 2, metadata !"Objective-C GC Only",
metadata !{
metadata !"Objective-C Garbage Collection", i32 2
}
}
!llvm.module.flags = !{ !0, !1, !2, !3, !4 }
</pre>
</div>
</div>

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@ -930,6 +930,71 @@ bool AsmPrinter::doFinalization(Module &M) {
if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
OutStreamer.SwitchSection(S);
// If we have module flags, then emit them.
NamedMDNode *ModFlags = M.getNamedMetadata("llvm.module.flags");
if (ModFlags) {
const char *ObjCGCName = "Objective-C Garbage Collection";
const char *ObjCGCOnlyName = "Objective-C GC Only";
const char *ObjCImageInfoVersion = "Objective-C Image Info Version";
const char *ObjCImageInfoSec = "Objective-C Image Info Section";
MDNode *GC = 0;
MDNode *GCOnly = 0;
MDNode *ImageInfoVersion = 0;
MDNode *ImageInfoSec = 0;
for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
MDNode *MD = ModFlags->getOperand(I);
unsigned Behavior = cast<ConstantInt>(MD->getOperand(0))->getZExtValue();
(void) Behavior;
MDString *Str = cast<MDString>(MD->getOperand(1));
if (Str->getString() == ObjCImageInfoVersion) {
assert(Behavior == 1 && "Invalid behavior for module flag!");
ImageInfoVersion = MD;
} else if (Str->getString() == ObjCGCName) {
assert((Behavior == 1 || Behavior == 3) &&
"Invalid behavior for module flag!");
GC = MD;
} else if (Str->getString() == ObjCGCOnlyName) {
if (Behavior == 2) continue; // Ignore the 'require' clause.
GCOnly = MD;
} else if (Str->getString() == ObjCImageInfoSec) {
assert(Behavior == 1 && "Invalid behavior for module flag!");
ImageInfoSec = MD;
}
}
if (ImageInfoVersion || GC || GCOnly || ImageInfoSec) {
// FIXME: Duh!
unsigned version = 0;
unsigned flags = 0;
version =
cast<ConstantInt>(ImageInfoVersion->getOperand(2))->getZExtValue();
if (GC)
flags |= cast<ConstantInt>(GC->getOperand(2))->getZExtValue();
if (GCOnly)
flags |= cast<ConstantInt>(GCOnly->getOperand(2))->getZExtValue();
Type *Int32Ty = Type::getInt32Ty(M.getContext());
Constant *values[2] = {
ConstantInt::get(Int32Ty, version),
ConstantInt::get(Int32Ty, flags)
};
ArrayType *AT = ArrayType::get(Int32Ty, 2);
StringRef Sec = cast<MDString>(ImageInfoSec->getOperand(2))->getString();
GlobalVariable *GV =
cast<GlobalVariable>(M.getOrInsertGlobal("L_OBJC_IMAGE_INFO", AT));
GV->setConstant(true);
GV->setSection(Sec);
GV->setInitializer(ConstantArray::get(AT, values));
EmitGlobalVariable(GV);
}
}
// Allow the target to emit any magic that it wants at the end of the file,
// after everything else has gone out.
EmitEndOfAsmFile(M);

View File

@ -455,26 +455,19 @@ encodeCompactUnwindRegistersWithFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
};
const unsigned *CURegs = (Is64Bit ? CU64BitRegs : CU32BitRegs);
// FIXME: The code below is WRONG and breaks tests on i386, see
// SingleSource/Regression/C++/EH/ctor_dtor_count.exec
// SingleSource/Regression/C++/EH/exception_spec_test.exec
// SingleSource/Regression/C++/EH/function_try_block.exec
// SingleSource/Regression/C++/EH/throw_rethrow_test.exec
return ~0U;
// Encode the registers in the order they were saved, 3-bits per register. The
// registers are numbered from 1 to 6.
// registers are numbered from 1 to CU_NUM_SAVED_REGS.
uint32_t RegEnc = 0;
for (int I = 0; I != 6; ++I) {
for (int I = CU_NUM_SAVED_REGS, Idx = 0; I != -1; --I) {
unsigned Reg = SavedRegs[I];
if (Reg == 0) break;
if (Reg == 0) continue;
int CURegNum = getCompactUnwindRegNum(CURegs, Reg);
if (CURegNum == -1)
return ~0U;
if (CURegNum == -1) return ~0U;
// Encode the 3-bit register number in order, skipping over 3-bits for each
// register.
RegEnc |= (CURegNum & 0x7) << ((5 - I) * 3);
RegEnc |= (CURegNum & 0x7) << (Idx++ * 3);
}
assert((RegEnc & 0x3FFFF) == RegEnc && "Invalid compact register encoding!");