Update after the bugfix about writing below SP

Author: momchil-velikov

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -2726,15 +2726,8 @@ AArch64TargetLowering::EmitDynamicProbedAlloc(MachineInstr &MI,
   const AArch64InstrInfo &TII =
       *MF.getSubtarget<AArch64Subtarget>().getInstrInfo();
   Register TargetReg = MI.getOperand(0).getReg();
-  MachineBasicBlock::iterator NextInst =
-      TII.insertStackProbingLoop(MBBI, AArch64::SP, TargetReg);
-
-  // MOV SP, TargetReg
-  BuildMI(*NextInst->getParent(), std::next(NextInst), DL,
-          TII.get(AArch64::ADDXri), AArch64::SP)
-      .addReg(TargetReg)
-      .addImm(0)
-      .addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0));
+  MachineBasicBlock::iterator NextInst = TII.probedStackAlloc(MBBI, TargetReg);
+
   MI.eraseFromParent();
   return NextInst->getParent();
 }

llvm/test/CodeGen/AArch64/stack-probing-dynamic.ll

@@ -26,8 +26,8 @@ define void @dynamic(i64 %size, ptr %out) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB0_1
 ; CHECK-NEXT:  .LBB0_3:
-; CHECK-NEXT:    str xzr, [x8]
 ; CHECK-NEXT:    mov sp, x8
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    str x8, [x1]
 ; CHECK-NEXT:    mov sp, x29
 ; CHECK-NEXT:    .cfi_def_cfa wsp, 16
@@ -70,8 +70,8 @@ define void @dynamic_fixed(i64 %size, ptr %out1, ptr %out2) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB1_1
 ; CHECK-NEXT:  .LBB1_3:
-; CHECK-NEXT:    str xzr, [x8]
 ; CHECK-NEXT:    mov sp, x8
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    str x8, [x2]
 ; CHECK-NEXT:    mov sp, x29
 ; CHECK-NEXT:    .cfi_def_cfa wsp, 16
@@ -120,8 +120,8 @@ define void @dynamic_align_64(i64 %size, ptr %out) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB2_1
 ; CHECK-NEXT:  .LBB2_3:
-; CHECK-NEXT:    str xzr, [x8]
 ; CHECK-NEXT:    mov sp, x8
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    str x8, [x1]
 ; CHECK-NEXT:    mov sp, x29
 ; CHECK-NEXT:    .cfi_def_cfa wsp, 32
@@ -163,12 +163,12 @@ define void @dynamic_align_8192(i64 %size, ptr %out) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB3_1
 ; CHECK-NEXT:  .LBB3_3:
-; CHECK-NEXT:    str xzr, [x9]
 ; CHECK-NEXT:    mov sp, x9
 ; CHECK-NEXT:    add x9, x0, #15
 ; CHECK-NEXT:    mov x8, sp
-; CHECK-NEXT:    mov x19, sp
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    and x9, x9, #0xfffffffffffffff0
+; CHECK-NEXT:    mov x19, sp
 ; CHECK-NEXT:    sub x8, x8, x9
 ; CHECK-NEXT:    and x8, x8, #0xffffffffffffe000
 ; CHECK-NEXT:  .LBB3_4: // =>This Inner Loop Header: Depth=1
@@ -179,8 +179,8 @@ define void @dynamic_align_8192(i64 %size, ptr %out) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB3_4
 ; CHECK-NEXT:  .LBB3_6:
-; CHECK-NEXT:    str xzr, [x8]
 ; CHECK-NEXT:    mov sp, x8
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    str x8, [x1]
 ; CHECK-NEXT:    mov sp, x29
 ; CHECK-NEXT:    .cfi_def_cfa wsp, 32
@@ -219,8 +219,8 @@ define void @dynamic_64k_guard(i64 %size, ptr %out) #0 "stack-probe-size"="65536
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB4_1
 ; CHECK-NEXT:  .LBB4_3:
-; CHECK-NEXT:    str xzr, [x8]
 ; CHECK-NEXT:    mov sp, x8
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    str x8, [x1]
 ; CHECK-NEXT:    mov sp, x29
 ; CHECK-NEXT:    .cfi_def_cfa wsp, 16
@@ -263,8 +263,8 @@ define void @no_reserved_call_frame(i64 %n) #0 {
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    b .LBB5_1
 ; CHECK-NEXT:  .LBB5_3: // %entry
-; CHECK-NEXT:    str xzr, [x0]
 ; CHECK-NEXT:    mov sp, x0
+; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    sub sp, sp, #1104
 ; CHECK-NEXT:    str xzr, [sp]
 ; CHECK-NEXT:    bl callee_stack_args