1 ; RUN: llc < %s -mtriple=x86_64-linux | FileCheck %s --check-prefix=CHECK 2 3 ; Test how we handle pathologically large stack frames when RAX is live through 4 ; the prologue and epilogue. 5 6 declare void @bar(i8*) 7 declare void @llvm.va_start(i8*) 8 9 ; For stack frames between 2GB and 16GB, do multiple adjustments. 10 11 define i32 @stack_frame_8gb(i32 %x, ...) nounwind { 12 ; CHECK-LABEL: stack_frame_8gb: 13 ; CHECK: subq ${{.*}}, %rsp # imm = 0x7FFFFFFF 14 ; CHECK: subq ${{.*}}, %rsp # imm = 0x7FFFFFFF 15 ; CHECK: subq ${{.*}}, %rsp # imm = 0x7FFFFFFF 16 ; CHECK: subq ${{.*}}, %rsp # imm = 0x7FFFFFFF 17 ; CHECK: subq ${{.*}}, %rsp 18 ; CHECK: callq bar 19 ; CHECK: addq ${{.*}}, %rsp # imm = 0x7FFFFFFF 20 ; CHECK: addq ${{.*}}, %rsp # imm = 0x7FFFFFFF 21 ; CHECK: addq ${{.*}}, %rsp # imm = 0x7FFFFFFF 22 ; CHECK: addq ${{.*}}, %rsp # imm = 0x7FFFFFFF 23 ; CHECK: addq ${{.*}}, %rsp 24 ; CHECK: retq 25 %1 = alloca [u0x200000000 x i8] 26 %va = alloca i8, i32 24 27 call void @llvm.va_start(i8* %va) 28 %2 = getelementptr inbounds [u0x200000000 x i8], [u0x200000000 x i8]* %1, i32 0, i32 0 29 call void @bar(i8* %2) 30 ret i32 %x 31 } 32 33 ; For stack frames larger than 16GB, spill EAX instead of doing a linear number 34 ; of adjustments. 35 36 ; This function should have a frame size of 0x4000000D0. The 0xD0 is 208 bytes 37 ; from 24 bytes of va_list, 176 bytes of spilled varargs regparms, and 8 bytes 38 ; of alignment. We subtract 8 less and add 8 more in the prologue and epilogue 39 ; respectively to account for the PUSH. 40 41 define i32 @stack_frame_16gb(i32 %x, ...) nounwind { 42 ; CHECK-LABEL: stack_frame_16gb: 43 ; CHECK: pushq %rax 44 ; CHECK-NEXT: movabsq ${{.*}}, %rax # imm = 0xFFFFFFFBFFFFFF38 45 ; CHECK-NEXT: addq %rsp, %rax 46 ; CHECK-NEXT: xchgq %rax, (%rsp) 47 ; CHECK-NEXT: movq (%rsp), %rsp 48 ; CHECK: callq bar 49 ; CHECK: pushq %rax 50 ; CHECK-NEXT: movabsq ${{.*}}, %rax # imm = 0x4000000D8 51 ; CHECK-NEXT: addq %rsp, %rax 52 ; CHECK-NEXT: xchgq %rax, (%rsp) 53 ; CHECK-NEXT: movq (%rsp), %rsp 54 ; CHECK: retq 55 %1 = alloca [u0x400000000 x i8] 56 %va = alloca i8, i32 24 57 call void @llvm.va_start(i8* %va) 58 %2 = getelementptr inbounds [u0x400000000 x i8], [u0x400000000 x i8]* %1, i32 0, i32 0 59 call void @bar(i8* %2) 60 ret i32 %x 61 } 62 63
