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 %argidx1 = getelementptr inbounds <{ %struct.S }>, <{ %struct.S }>* %argmem, i32 0, i32 0, i32 0, i32 0 19 %argidx2 = getelementptr inbounds <{ %struct.S }>, <{ %struct.S }>* %argmem, i32 0, i32 0, i32 0, i32 1 20 store i8 42, i8* %argidx2, align 4 21 br i1 %x, label %bb1, label %bb2 22 23bb1: 24 store i8 42, i8* %argidx1, align 4 25 br label %bb2 26 27bb2: 28 call void @inalloca_params(<{ %struct.S }>* inalloca nonnull %argmem) 29 ret void 30} 31 32; CHECK-LABEL: _call_inalloca: # @call_inalloca 33; CHECK: pushl %ebp 34; CHECK: movl %esp, %ebp 35; CHECK: movl $8192, %eax 36; CHECK: calll __chkstk 37; CHECK: calll _inalloca_params 38; CHECK: movl %ebp, %esp 39; CHECK: popl %ebp 40; CHECK: retl 41 42declare void @inalloca_params(<{ %struct.S }>* inalloca) 43 44declare i32 @doSomething(i32, i32*) 45 46; In this test case, we force usage of EAX before the prologue, and have to 47; compensate before calling __chkstk. It would also be valid for us to avoid 48; shrink wrapping in this case. 49 50define x86_fastcallcc i32 @use_eax_before_prologue(i32 inreg %a, i32 inreg %b) { 51 %tmp = alloca i32, i32 1024, align 4 52 %tmp2 = icmp slt i32 %a, %b 53 br i1 %tmp2, label %true, label %false 54 55true: 56 store i32 %a, i32* %tmp, align 4 57 %tmp4 = call i32 @doSomething(i32 0, i32* %tmp) 58 br label %false 59 60false: 61 %tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ] 62 ret i32 %tmp.0 63} 64 65; CHECK-LABEL: @use_eax_before_prologue@8: # @use_eax_before_prologue 66; CHECK: movl %ecx, %eax 67; CHECK: cmpl %edx, %ecx 68; CHECK: jge LBB1_2 69; CHECK: pushl %eax 70; CHECK: movl $4092, %eax 71; CHECK: calll __chkstk 72; CHECK: movl 4092(%esp), %eax 73; CHECK: calll _doSomething 74; CHECK: LBB1_2: 75; CHECK: retl 76