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1; RUN: llc -O0 -mtriple=x86_64-apple-darwin %s -o - | FileCheck %s2declare void @foo(i32, ...)3 4declare i32 @__gxx_personality_v0(...)5 6; We were running out of registers for this invoke, because:7 8; 1. The lshr/and pattern gets matched to a no-REX MOV so that ah/bh/... can9; be used instead, cutting available registers for %b.arg down to eax, ebx,10; ecx, edx, esi, edi.11; 2. We have a base pointer taking ebx out of contention.12; 3. The landingpad block convinced us we should be defining rax here.13; 3. The al fiddling for the varargs call only noted down that al was spillable,14; not ah or hax.15;16; So by the time we need to allocate a register for the call all registers are17; tied up and unspillable.18 19; CHECK-LABEL: bar:20; CHECK: xorl %edi, %edi21; CHECK: movb %dil, {{[0-9]+}}(%rbx)22; CHECK: movb {{[0-9]+}}(%rbx), %al23 24define i32 @bar(i32 %a, i32 %b, i32 %c, i32 %d, ...) personality ptr @__gxx_personality_v0 {25 %mem = alloca i32, i32 %a, align 32 ; Force rbx to be used as a base pointer26 %b.tmp = lshr i32 %b, 827 %b.arg = and i32 %b.tmp, 25528 invoke void(i32, ...) @foo(i32 42, ptr %mem, i32 %c, i32 %d, i32 %b.arg) to label %success unwind label %fail29 30success:31 ret i32 032fail:33 %exc = landingpad { ptr, i32 } cleanup34 %res = extractvalue { ptr, i32 } %exc, 135 ret i32 %res36}37 38; CHECK-LABEL: live:39; CHECK: movl {{%.*}}, %eax40 41define i32 @live(i32 %a, i32 %b, i32 %c, i32 %d, ...) personality ptr @__gxx_personality_v0 {42 %mem = alloca i32, i32 %a, align 32 ; Force rbx to be used as a base pointer43 %b.tmp = lshr i32 %b, 844 %b.arg = and i32 %b.tmp, 25545 invoke void(i32, ...) @foo(i32 42) to label %success unwind label %fail46 47success:48 ret i32 049fail:50 %exc = landingpad { ptr, i32 } cleanup51 %res = extractvalue { ptr, i32 } %exc, 152 ret i32 %b.arg53}54