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-rw-r--r--docs/LangRef.html6
-rw-r--r--include/llvm/Target/TargetData.h6
-rw-r--r--lib/Target/ARM/ARMTargetMachine.cpp15
-rw-r--r--lib/Target/TargetData.cpp12
-rw-r--r--lib/Target/X86/README-SSE.txt2
-rw-r--r--lib/Target/X86/README.txt2
-rw-r--r--lib/Target/X86/X86TargetMachine.cpp8
-rw-r--r--lib/Transforms/Utils/Local.cpp8
8 files changed, 45 insertions, 14 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 1392db6e60..a28d92efa1 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -1319,6 +1319,12 @@ target datalayout = "<i>layout specification</i>"
the bits with the least significance have the lowest address
location.</dd>
+ <dt><tt>S<i>size</i></tt></dt>
+ <dd>Specifies the natural alignment of the stack in bits. Alignment promotion
+ of stack variables is limited to the natural stack alignment to avoid
+ dynamic stack realignment. The stack alignment must be a multiple of
+ 8-bits, and currently defaults to 128 bits if unspecified.</dd>
+
<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
<i>preferred</i> alignments. All sizes are in bits. Specifying
diff --git a/include/llvm/Target/TargetData.h b/include/llvm/Target/TargetData.h
index 315bee96ba..e34094ddb7 100644
--- a/include/llvm/Target/TargetData.h
+++ b/include/llvm/Target/TargetData.h
@@ -70,6 +70,7 @@ private:
unsigned PointerMemSize; ///< Pointer size in bytes
unsigned PointerABIAlign; ///< Pointer ABI alignment
unsigned PointerPrefAlign; ///< Pointer preferred alignment
+ unsigned StackNaturalAlign; ///< Stack natural alignment
SmallVector<unsigned char, 8> LegalIntWidths; ///< Legal Integers.
@@ -163,6 +164,11 @@ public:
return !isLegalInteger(Width);
}
+ /// Returns true if the given alignment exceeds the natural stack alignment.
+ bool exceedsNaturalStackAlignment(unsigned Align) const {
+ return (StackNaturalAlign != 0) && (Align > StackNaturalAlign);
+ }
+
/// fitsInLegalInteger - This function returns true if the specified type fits
/// in a native integer type supported by the CPU. For example, if the CPU
/// only supports i32 as a native integer type, then i27 fits in a legal
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index f779ede3e3..96b1e89b0d 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -53,9 +53,12 @@ ARMTargetMachine::ARMTargetMachine(const Target &T, StringRef TT,
: ARMBaseTargetMachine(T, TT, CPU, FS, RM, CM), InstrInfo(Subtarget),
DataLayout(Subtarget.isAPCS_ABI() ?
std::string("e-p:32:32-f64:32:64-i64:32:64-"
- "v128:32:128-v64:32:64-n32") :
+ "v128:32:128-v64:32:64-n32-S32") :
+ Subtarget.isAAPCS_ABI() ?
std::string("e-p:32:32-f64:64:64-i64:64:64-"
- "v128:64:128-v64:64:64-n32")),
+ "v128:64:128-v64:64:64-n32-S64") :
+ std::string("e-p:32:32-f64:64:64-i64:64:64-"
+ "v128:64:128-v64:64:64-n32-S32")),
ELFWriterInfo(*this),
TLInfo(*this),
TSInfo(*this),
@@ -75,10 +78,14 @@ ThumbTargetMachine::ThumbTargetMachine(const Target &T, StringRef TT,
DataLayout(Subtarget.isAPCS_ABI() ?
std::string("e-p:32:32-f64:32:64-i64:32:64-"
"i16:16:32-i8:8:32-i1:8:32-"
- "v128:32:128-v64:32:64-a:0:32-n32") :
+ "v128:32:128-v64:32:64-a:0:32-n32-S32") :
+ Subtarget.isAAPCS_ABI() ?
+ std::string("e-p:32:32-f64:64:64-i64:64:64-"
+ "i16:16:32-i8:8:32-i1:8:32-"
+ "v128:64:128-v64:64:64-a:0:32-n32-S64") :
std::string("e-p:32:32-f64:64:64-i64:64:64-"
"i16:16:32-i8:8:32-i1:8:32-"
- "v128:64:128-v64:64:64-a:0:32-n32")),
+ "v128:64:128-v64:64:64-a:0:32-n32-S32")),
ELFWriterInfo(*this),
TLInfo(*this),
TSInfo(*this),
diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index 1dfd9a83da..bd6a6b67be 100644
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -139,6 +139,7 @@ void TargetData::init(StringRef Desc) {
PointerMemSize = 8;
PointerABIAlign = 8;
PointerPrefAlign = PointerABIAlign;
+ StackNaturalAlign = 0;
// Default alignments
setAlignment(INTEGER_ALIGN, 1, 1, 1); // i1
@@ -218,7 +219,12 @@ void TargetData::init(StringRef Desc) {
Token = Split.second;
} while (!Specifier.empty() || !Token.empty());
break;
-
+ case 'S': // Stack natural alignment.
+ StackNaturalAlign = getInt(Specifier.substr(1));
+ StackNaturalAlign /= 8;
+ // FIXME: Should we really be truncating these alingments and
+ // sizes silently?
+ break;
default:
break;
}
@@ -372,7 +378,9 @@ std::string TargetData::getStringRepresentation() const {
OS << (LittleEndian ? "e" : "E")
<< "-p:" << PointerMemSize*8 << ':' << PointerABIAlign*8
- << ':' << PointerPrefAlign*8;
+ << ':' << PointerPrefAlign*8
+ << "-S" << StackNaturalAlign*8;
+
for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
const TargetAlignElem &AI = Alignments[i];
OS << '-' << (char)AI.AlignType << AI.TypeBitWidth << ':'
diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt
index f16ec029e9..7d901afae4 100644
--- a/lib/Target/X86/README-SSE.txt
+++ b/lib/Target/X86/README-SSE.txt
@@ -862,7 +862,7 @@ define float @bar(float %x) nounwind {
This IR (from PR6194):
-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"
+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-apple-darwin10.0.0"
%0 = type { double, double }
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index b98f5fbb99..b407955060 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -1217,7 +1217,7 @@ Also check why xmm7 is not used at all in the function.
Take the following:
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-S128"
target triple = "i386-apple-darwin8"
@in_exit.4870.b = internal global i1 false ; <i1*> [#uses=2]
define fastcc void @abort_gzip() noreturn nounwind {
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 683d6aa0dd..1dcad35c2e 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -34,11 +34,11 @@ X86_32TargetMachine::X86_32TargetMachine(const Target &T, StringRef TT,
Reloc::Model RM, CodeModel::Model CM)
: X86TargetMachine(T, TT, CPU, FS, RM, CM, false),
DataLayout(getSubtargetImpl()->isTargetDarwin() ?
- "e-p:32:32-f64:32:64-i64:32:64-f80:128:128-f128:128:128-n8:16:32" :
+ "e-p:32:32-f64:32:64-i64:32:64-f80:128:128-f128:128:128-n8:16:32-S128" :
(getSubtargetImpl()->isTargetCygMing() ||
getSubtargetImpl()->isTargetWindows()) ?
- "e-p:32:32-f64:64:64-i64:64:64-f80:32:32-f128:128:128-n8:16:32" :
- "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-f128:128:128-n8:16:32"),
+ "e-p:32:32-f64:64:64-i64:64:64-f80:32:32-f128:128:128-n8:16:32-S32" :
+ "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-f128:128:128-n8:16:32-S32"),
InstrInfo(*this),
TSInfo(*this),
TLInfo(*this),
@@ -50,7 +50,7 @@ X86_64TargetMachine::X86_64TargetMachine(const Target &T, StringRef TT,
StringRef CPU, StringRef FS,
Reloc::Model RM, CodeModel::Model CM)
: X86TargetMachine(T, TT, CPU, FS, RM, CM, true),
- DataLayout("e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128-f128:128:128-n8:16:32:64"),
+ DataLayout("e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128-f128:128:128-n8:16:32:64-S128"),
InstrInfo(*this),
TSInfo(*this),
TLInfo(*this),
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index be0aa82500..7034feb227 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -721,10 +721,14 @@ bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) {
/// their preferred alignment from the beginning.
///
static unsigned enforceKnownAlignment(Value *V, unsigned Align,
- unsigned PrefAlign) {
+ unsigned PrefAlign, const TargetData *TD) {
V = V->stripPointerCasts();
if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
+ // If the preferred alignment is greater than the natural stack alignment
+ // then don't round up. This avoids dynamic stack realignment.
+ if (TD && TD->exceedsNaturalStackAlignment(PrefAlign))
+ return Align;
// If there is a requested alignment and if this is an alloca, round up.
if (AI->getAlignment() >= PrefAlign)
return AI->getAlignment();
@@ -775,7 +779,7 @@ unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign,
Align = std::min(Align, +Value::MaximumAlignment);
if (PrefAlign > Align)
- Align = enforceKnownAlignment(V, Align, PrefAlign);
+ Align = enforceKnownAlignment(V, Align, PrefAlign, TD);
// We don't need to make any adjustment.
return Align;
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-16 05:41:29 +0000