; RUN: llc < %s -enable-shrink-wrap=true | FileCheck %s ; chkstk cannot come before the usual prologue, since it adjusts ESP. ; If chkstk is used in the prologue, we also have to be careful about preserving ; EAX if it is used. target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" target triple = "i686-pc-windows-msvc18.0.0" %struct.S = type { [8192 x i8] } define x86_thiscallcc void @call_inalloca(i1 %x) { entry: %argmem = alloca inalloca <{ %struct.S }>, align 4 %argidx1 = getelementptr inbounds <{ %struct.S }>, <{ %struct.S }>* %argmem, i32 0, i32 0, i32 0, i32 0 %argidx2 = getelementptr inbounds <{ %struct.S }>, <{ %struct.S }>* %argmem, i32 0, i32 0, i32 0, i32 1 store i8 42, i8* %argidx2, align 4 br i1 %x, label %bb1, label %bb2 bb1: store i8 42, i8* %argidx1, align 4 br label %bb2 bb2: call void @inalloca_params(<{ %struct.S }>* inalloca nonnull %argmem) ret void } ; CHECK-LABEL: _call_inalloca: # @call_inalloca ; CHECK: pushl %ebp ; CHECK: movl %esp, %ebp ; CHECK: movl $8192, %eax ; CHECK: calll __chkstk ; CHECK: calll _inalloca_params ; CHECK: movl %ebp, %esp ; CHECK: popl %ebp ; CHECK: retl declare void @inalloca_params(<{ %struct.S }>* inalloca) declare i32 @doSomething(i32, i32*) ; In this test case, we force usage of EAX before the prologue, and have to ; compensate before calling __chkstk. It would also be valid for us to avoid ; shrink wrapping in this case. define x86_fastcallcc i32 @use_eax_before_prologue(i32 inreg %a, i32 inreg %b) { %tmp = alloca i32, i32 1024, align 4 %tmp2 = icmp slt i32 %a, %b br i1 %tmp2, label %true, label %false true: store i32 %a, i32* %tmp, align 4 %tmp4 = call i32 @doSomething(i32 0, i32* %tmp) br label %false false: %tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ] ret i32 %tmp.0 } ; CHECK-LABEL: @use_eax_before_prologue@8: # @use_eax_before_prologue ; CHECK: movl %ecx, %eax ; CHECK: cmpl %edx, %eax ; CHECK: jge LBB1_2 ; CHECK: pushl %eax ; CHECK: movl $4092, %eax ; CHECK: calll __chkstk ; CHECK: movl 4092(%esp), %eax ; CHECK: calll _doSomething ; CHECK: LBB1_2: ; CHECK: retl