XCore target: Optimise entsp / retsp selection

llvm-svn: 198612
This commit is contained in:
Robert Lytton 2014-01-06 14:20:47 +00:00
parent a53360a339
commit cbb588a264
3 changed files with 19 additions and 10 deletions

View File

@ -427,12 +427,20 @@ processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR);
// If we need to extend the stack it is more efficient to use entsp / retsp.
// We force the LR to be saved so these instructions are used.
if (!LRUsed && !MF.getFunction()->isVarArg() &&
MF.getFrameInfo()->estimateStackSize(MF))
LRUsed = true;
// We will handling LR in the prologue/epilogue
// and space on the stack ourselves.
if (MF.getRegInfo().isPhysRegUsed(XCore::LR)) {
if (LRUsed) {
MF.getRegInfo().setPhysRegUnused(XCore::LR);
XFI->createLRSpillSlot(MF);
}
// A callee save register is used to hold the FP.
// This needs saving / restoring in the epilogue / prologue.
if (hasFP(MF))

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@ -61,9 +61,11 @@ entry:
; FP + large frame: spill FP+SR = entsp 2 + 100000
; CHECKFP-LABEL: f4
; CHECKFP: extsp 65535
; CHECKFP: entsp 65535
; CHECKFP-NEXT: .Ltmp{{[0-9]+}}
; CHECKFP-NEXT: .cfi_def_cfa_offset 262140
; CHECKFP-NEXT: .Ltmp{{[0-9]+}}
; CHECKFP-NEXT: .cfi_offset 15, 0
; CHECKFP-NEXT: extsp 34467
; CHECKFP-NEXT: .Ltmp{{[0-9]+}}
; CHECKFP-NEXT: .cfi_def_cfa_offset 400008
@ -76,20 +78,20 @@ entry:
; CHECKFP-NEXT: set sp, r10
; CHECKFP-NEXT: ldw r10, sp[1]
; CHECKFP-NEXT: ldaw sp, sp[65535]
; CHECKFP-NEXT: ldaw sp, sp[34467]
; CHECKFP-NEXT: retsp 0
; CHECKFP-NEXT: retsp 34467
;
; !FP + large frame: spill SR+SR = entsp 2 + 100000
; CHECK-LABEL: f4
; CHECK: extsp 65535
; CHECK: entsp 65535
; CHECK-NEXT: .Ltmp{{[0-9]+}}
; CHECK-NEXT: .cfi_def_cfa_offset 262140
; CHECK-NEXT: .Ltmp{{[0-9]+}}
; CHECK-NEXT: .cfi_offset 15, 0
; CHECK-NEXT: extsp 34467
; CHECK-NEXT: .Ltmp{{[0-9]+}}
; CHECK-NEXT: .cfi_def_cfa_offset 400008
; CHECK-NEXT: ldaw sp, sp[65535]
; CHECK-NEXT: ldaw sp, sp[34467]
; CHECK-NEXT: retsp 0
; CHECK-NEXT: retsp 34467
define void @f4() {
entry:
%0 = alloca [100000 x i32]

View File

@ -69,7 +69,7 @@ declare void @g(i32*, i32*)
; CHECK: .text
; !FP + large frame: spill SR+SR = entsp 2 + 100000
; CHECK-LABEL: ScavengeSlots:
; CHECK: extsp 65535
; CHECK: entsp 65535
; CHECK: extsp 34467
; scavenge r11
; CHECK: ldaw r11, sp[0]
@ -97,10 +97,9 @@ declare void @g(i32*, i32*)
; CHECK: ldw r1, cp{{\[}}[[INDEX4]]{{\]}}
; CHECK: stw r11, r0[r1]
; CHECK: ldaw sp, sp[65535]
; CHECK: ldaw sp, sp[34467]
; CHECK: ldw r4, sp[1]
; CHECK: ldw r5, sp[0]
; CHECK: retsp 0
; CHECK: retsp 34467
define void @ScavengeSlots(i32 %r0, i32 %r1, i32 %r2, i32 %r3, i32 %r4) nounwind {
entry:
%Data = alloca [100000 x i32]