Add support for the 'alignstack' attribute to the x86 backend. Fixes PR5254.
Also, FileCheck'ize a test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96686 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index f141c56..4377d5b 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -95,6 +95,9 @@
MFInfo = 0;
FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
MachineFrameInfo(*TM.getFrameInfo());
+ if (Fn->hasFnAttr(Attribute::StackAlignment))
+ FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
+ Fn->getAttributes().getFnAttributes()));
ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
MachineConstantPool(TM.getTargetData());
Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 8524236..45ff297 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -446,8 +446,10 @@
bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const Function *F = MF.getFunction();
bool requiresRealignment =
- RealignStack && (MFI->getMaxAlignment() > StackAlign);
+ RealignStack && ((MFI->getMaxAlignment() > StackAlign) ||
+ F->hasFnAttr(Attribute::StackAlignment));
// FIXME: Currently we don't support stack realignment for functions with
// variable-sized allocas.
diff --git a/test/CodeGen/X86/stack-align.ll b/test/CodeGen/X86/stack-align.ll
index cb65e9b..e971ef7 100644
--- a/test/CodeGen/X86/stack-align.ll
+++ b/test/CodeGen/X86/stack-align.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -relocation-model=static -mcpu=yonah | grep {andpd.*4(%esp), %xmm}
+; RUN: llc < %s -relocation-model=static -realign-stack=1 -mcpu=yonah | FileCheck %s
; The double argument is at 4(esp) which is 16-byte aligned, allowing us to
; fold the load into the andpd.
@@ -12,6 +12,7 @@
%tmp = getelementptr { double, double }* %z, i32 0, i32 0 ; <double*> [#uses=1]
%tmp1 = load double* %tmp, align 8 ; <double> [#uses=1]
%tmp2 = tail call double @fabs( double %tmp1 ) ; <double> [#uses=1]
+ ; CHECK: andpd{{.*}}4(%esp), %xmm
%tmp3 = load double* @G, align 16 ; <double> [#uses=1]
%tmp4 = tail call double @fabs( double %tmp3 ) ; <double> [#uses=1]
%tmp6 = fadd double %tmp4, %tmp2 ; <double> [#uses=1]
@@ -19,4 +20,20 @@
ret void
}
+define void @test2() alignstack(16) {
+entry:
+ ; CHECK: andl{{.*}}$-16, %esp
+ ret void
+}
+
+; Use a call to force a spill.
+define <2 x double> @test3(<2 x double> %x, <2 x double> %y) alignstack(32) {
+entry:
+ ; CHECK: andl{{.*}}$-32, %esp
+ call void @test2()
+ %A = mul <2 x double> %x, %y
+ ret <2 x double> %A
+}
+
declare double @fabs(double)
+