1; RUN: llc < %s -enable-shrink-wrap=true | FileCheck %s 2 3; TODO: add preallocated versions of tests 4; we don't yet support conditionally called preallocated calls after the setup 5 6; chkstk cannot come before the usual prologue, since it adjusts ESP. 7; If chkstk is used in the prologue, we also have to be careful about preserving 8; EAX if it is used. 9 10target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" 11target triple = "i686-pc-windows-msvc18.0.0" 12 13%struct.S = type { [8192 x i8] } 14 15define x86_thiscallcc void @call_inalloca(i1 %x) { 16entry: 17 %argmem = alloca inalloca <{ %struct.S }>, align 4 18 %argidx2 = getelementptr inbounds <{ %struct.S }>, ptr %argmem, i32 0, i32 0, i32 0, i32 1 19 store i8 42, ptr %argidx2, align 4 20 br i1 %x, label %bb1, label %bb2 21 22bb1: 23 store i8 42, ptr %argmem, align 4 24 br label %bb2 25 26bb2: 27 call void @inalloca_params(ptr inalloca(<{ %struct.S }>) nonnull %argmem) 28 ret void 29} 30 31; CHECK-LABEL: _call_inalloca: # @call_inalloca 32; CHECK: pushl %ebp 33; CHECK: movl %esp, %ebp 34; CHECK: movl $8192, %eax 35; CHECK: calll __chkstk 36; CHECK: calll _inalloca_params 37; CHECK: movl %ebp, %esp 38; CHECK: popl %ebp 39; CHECK: retl 40 41declare void @inalloca_params(ptr inalloca(<{ %struct.S }>)) 42 43declare i32 @doSomething(i32, ptr) 44 45; In this test case, we force usage of EAX before the prologue, and have to 46; compensate before calling __chkstk. It would also be valid for us to avoid 47; shrink wrapping in this case. 48 49define x86_fastcallcc i32 @use_eax_before_prologue(i32 inreg %a, i32 inreg %b) { 50 %tmp = alloca i32, i32 1024, align 4 51 %tmp2 = icmp slt i32 %a, %b 52 br i1 %tmp2, label %true, label %false 53 54true: 55 store i32 %a, ptr %tmp, align 4 56 %tmp4 = call i32 @doSomething(i32 0, ptr %tmp) 57 br label %false 58 59false: 60 %tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ] 61 ret i32 %tmp.0 62} 63 64; CHECK-LABEL: @use_eax_before_prologue@8: # @use_eax_before_prologue 65; CHECK: movl %ecx, %eax 66; CHECK: cmpl %edx, %ecx 67; CHECK: jge LBB1_2 68; CHECK: pushl %eax 69; CHECK: movl $4092, %eax 70; CHECK: calll __chkstk 71; CHECK: movl 4092(%esp), %eax 72; CHECK: calll _doSomething 73; CHECK: LBB1_2: 74; CHECK: retl 75