Segmented stacks: omit __morestack call when there's no frame.

Patch by Florian Zeitz

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209436 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Tim Northover 2014-05-22 13:03:43 +00:00
parent 65ea1ad208
commit de70176f5f
5 changed files with 77 additions and 18 deletions

View File

@ -1746,6 +1746,12 @@ void ARMFrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
ARMFunctionInfo *ARMFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc DL;
uint64_t StackSize = MFI->getStackSize();
// Do not generate a prologue for functions with a stack of size zero
if (StackSize == 0)
return;
// Use R4 and R5 as scratch registers.
// We save R4 and R5 before use and restore them before leaving the function.
unsigned ScratchReg0 = ARM::R4;
@ -1775,8 +1781,6 @@ void ARMFrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
MF.push_front(PrevStackMBB);
// The required stack size that is aligned to ARM constant criterion.
uint64_t StackSize = MFI->getStackSize();
AlignedStackSize = alignToARMConstant(StackSize);
// When the frame size is less than 256 we just compare the stack

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@ -1176,6 +1176,15 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
!STI.isTargetWin32() && !STI.isTargetWin64() && !STI.isTargetFreeBSD())
report_fatal_error("Segmented stacks not supported on this platform.");
// Eventually StackSize will be calculated by a link-time pass; which will
// also decide whether checking code needs to be injected into this particular
// prologue.
StackSize = MFI->getStackSize();
// Do not generate a prologue for functions with a stack of size zero
if (StackSize == 0)
return;
MachineBasicBlock *allocMBB = MF.CreateMachineBasicBlock();
MachineBasicBlock *checkMBB = MF.CreateMachineBasicBlock();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
@ -1200,11 +1209,6 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
MF.push_front(allocMBB);
MF.push_front(checkMBB);
// Eventually StackSize will be calculated by a link-time pass; which will
// also decide whether checking code needs to be injected into this particular
// prologue.
StackSize = MFI->getStackSize();
// When the frame size is less than 256 we just compare the stack
// boundary directly to the value of the stack pointer, per gcc.
bool CompareStackPointer = StackSize < kSplitStackAvailable;

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@ -57,6 +57,8 @@ define void @test_basic() #0 {
define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
%addend = load i32 * %closure
%result = add i32 %other, %addend
%mem = alloca i32, i32 10
call void @dummy_use (i32* %mem, i32 10)
ret i32 %result
; ARM-linux: test_nested:
@ -68,7 +70,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; ARM-linux-NEXT: cmp r4, r5
; ARM-linux-NEXT: blo .LBB1_2
; ARM-linux: mov r4, #0
; ARM-linux: mov r4, #56
; ARM-linux-NEXT: mov r5, #0
; ARM-linux-NEXT: stmdb sp!, {lr}
; ARM-linux-NEXT: bl __morestack
@ -87,7 +89,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; ARM-android-NEXT: cmp r4, r5
; ARM-android-NEXT: blo .LBB1_2
; ARM-android: mov r4, #0
; ARM-android: mov r4, #56
; ARM-android-NEXT: mov r5, #0
; ARM-android-NEXT: stmdb sp!, {lr}
; ARM-android-NEXT: bl __morestack
@ -234,4 +236,14 @@ define fastcc void @test_fastcc_large() #0 {
}
define void @test_nostack() #0 {
ret void
; ARM-linux-LABEL: test_nostack:
; ARM-linux-NOT: bl __morestack
; ARM-android-LABEL: test_nostack:
; ARM-android-NOT: bl __morestack
}
attributes #0 = { "split-stack" }

View File

@ -57,6 +57,8 @@ define void @test_basic() #0 {
define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
%addend = load i32 * %closure
%result = add i32 %other, %addend
%mem = alloca i32, i32 10
call void @dummy_use (i32* %mem, i32 10)
ret i32 %result
; Thumb-android: test_nested:
@ -68,7 +70,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; Thumb-android-NEXT: cmp r4, r5
; Thumb-android-NEXT: blo .LBB1_2
; Thumb-android: mov r4, #0
; Thumb-android: mov r4, #56
; Thumb-android-NEXT: mov r5, #0
; Thumb-android-NEXT: push {lr}
; Thumb-android-NEXT: bl __morestack
@ -88,7 +90,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; Thumb-linux-NEXT: cmp r4, r5
; Thumb-linux-NEXT: blo .LBB1_2
; Thumb-linux: mov r4, #0
; Thumb-linux: mov r4, #56
; Thumb-linux-NEXT: mov r5, #0
; Thumb-linux-NEXT: push {lr}
; Thumb-linux-NEXT: bl __morestack
@ -246,4 +248,14 @@ define fastcc void @test_fastcc_large() #0 {
}
define void @test_nostack() #0 {
ret void
; Thumb-android-LABEL: test_nostack:
; Thumb-android-NOT: bl __morestack
; Thumb-linux-LABEL: test_nostack:
; Thumb-linux-NOT: bl __morestack
}
attributes #0 = { "split-stack" }

View File

@ -107,13 +107,15 @@ define void @test_basic() #0 {
define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
%addend = load i32 * %closure
%result = add i32 %other, %addend
%mem = alloca i32, i32 10
call void @dummy_use (i32* %mem, i32 10)
ret i32 %result
; X32-Linux: cmpl %gs:48, %esp
; X32-Linux-NEXT: ja .LBB1_2
; X32-Linux: pushl $4
; X32-Linux-NEXT: pushl $0
; X32-Linux-NEXT: pushl $60
; X32-Linux-NEXT: calll __morestack
; X32-Linux-NEXT: ret
@ -121,7 +123,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X64-Linux-NEXT: ja .LBB1_2
; X64-Linux: movq %r10, %rax
; X64-Linux-NEXT: movabsq $0, %r10
; X64-Linux-NEXT: movabsq $56, %r10
; X64-Linux-NEXT: movabsq $0, %r11
; X64-Linux-NEXT: callq __morestack
; X64-Linux-NEXT: ret
@ -132,7 +134,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X32-Darwin-NEXT: ja LBB1_2
; X32-Darwin: pushl $4
; X32-Darwin-NEXT: pushl $0
; X32-Darwin-NEXT: pushl $60
; X32-Darwin-NEXT: calll ___morestack
; X32-Darwin-NEXT: ret
@ -140,7 +142,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X64-Darwin-NEXT: ja LBB1_2
; X64-Darwin: movq %r10, %rax
; X64-Darwin-NEXT: movabsq $0, %r10
; X64-Darwin-NEXT: movabsq $56, %r10
; X64-Darwin-NEXT: movabsq $0, %r11
; X64-Darwin-NEXT: callq ___morestack
; X64-Darwin-NEXT: ret
@ -150,7 +152,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X32-MinGW-NEXT: ja LBB1_2
; X32-MinGW: pushl $4
; X32-MinGW-NEXT: pushl $0
; X32-MinGW-NEXT: pushl $52
; X32-MinGW-NEXT: calll ___morestack
; X32-MinGW-NEXT: ret
@ -159,7 +161,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X64-MinGW-NEXT: ja .LBB1_2
; X64-MinGW: movq %r10, %rax
; X64-MinGW-NEXT: movabsq $0, %r10
; X64-MinGW-NEXT: movabsq $88, %r10
; X64-MinGW-NEXT: movabsq $32, %r11
; X64-MinGW-NEXT: callq __morestack
; X64-MinGW-NEXT: retq
@ -169,7 +171,7 @@ define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
; X64-FreeBSD-NEXT: ja .LBB1_2
; X64-FreeBSD: movq %r10, %rax
; X64-FreeBSD-NEXT: movabsq $0, %r10
; X64-FreeBSD-NEXT: movabsq $56, %r10
; X64-FreeBSD-NEXT: movabsq $0, %r11
; X64-FreeBSD-NEXT: callq __morestack
; X64-FreeBSD-NEXT: ret
@ -435,4 +437,29 @@ define fastcc void @test_fastcc_large_with_ecx_arg(i32 %a) #0 {
}
define void @test_nostack() #0 {
ret void
; X32-Linux-LABEL: test_nostack:
; X32-Linux-NOT: calll __morestack
; X64-Linux-LABEL: test_nostack:
; X32-Linux-NOT: callq __morestack
; X32-Darwin-LABEL: test_nostack:
; X32-Darwin-NOT: calll __morestack
; X64-Darwin-LABEL: test_nostack:
; X64-Darwin-NOT: callq __morestack
; X32-MinGW-LABEL: test_nostack:
; X32-MinGW-NOT: calll __morestack
; X64-MinGW-LABEL: test_nostack:
; X64-MinGW-NOT: callq __morestack
; X64-FreeBSD-LABEL: test_nostack:
; X64-FreeBSD-NOT: callq __morestack
}
attributes #0 = { "split-stack" }