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; RUN: opt -O2 -S < %s | FileCheck %s
;
; This test tries to ensure that simplifycfg hoisting common instructions
; of then/else branch indeed happens. BPF target has added an IR pass
; before loop optimizations as Commit 1d51dc38d89b
; ([SimplifyCFG][LoopRotate] SimplifyCFG: disable common instruction
; hoisting by default, enable late in pipeline)
; disabled common instruction hoisting. Due to optimization triggered
; code changes, later SimplifyCFG may not be able to perform optimization
; even common inst hoisting is enabled.
;
; Source:
; typedef struct {
; void *f_back;
; } FrameData;
; extern int get_data(void *, void *);
; extern void get_frame_ptr(void *);
; int test() {
; void *frame_ptr;
; FrameData frame;
;
; get_frame_ptr(&frame_ptr);
;
; #pragma nounroll
; for (int i = 0; i < 6; i++) {
; if (frame_ptr && get_data(frame_ptr, &frame)) {
; frame_ptr = frame.f_back;
; }
; }
; return frame_ptr == 0;
; }
; Compilation flag:
; clang -target bpf -O2 -Xclang -disable-llvm-passes -S -emit-llvm t.c -o t.ll
target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
target triple = "bpf"
%struct.FrameData = type { ptr }
; Function Attrs: nounwind
define dso_local i32 @test() #0 {
entry:
%frame_ptr = alloca ptr, align 8
%frame = alloca %struct.FrameData, align 8
%i = alloca i32, align 4
call void @llvm.lifetime.start.p0(i64 8, ptr %frame_ptr) #3
call void @llvm.lifetime.start.p0(i64 8, ptr %frame) #3
call void @get_frame_ptr(ptr %frame_ptr)
call void @llvm.lifetime.start.p0(i64 4, ptr %i) #3
store i32 0, ptr %i, align 4, !tbaa !2
br label %for.cond
; CHECK-LABEL: entry
; CHECK: %[[PTR:[0-9]+]] = load ptr, ptr %frame_ptr, align 8
; CHECK: %{{[0-9a-z.]+}} = icmp eq ptr %[[PTR]], null
; CHECK: br label
for.cond: ; preds = %for.inc, %entry
%0 = load i32, ptr %i, align 4, !tbaa !2
%cmp = icmp slt i32 %0, 6
br i1 %cmp, label %for.body, label %for.cond.cleanup
for.cond.cleanup: ; preds = %for.cond
call void @llvm.lifetime.end.p0(i64 4, ptr %i) #3
br label %for.end
for.body: ; preds = %for.cond
%1 = load ptr, ptr %frame_ptr, align 8, !tbaa !6
%tobool = icmp ne ptr %1, null
br i1 %tobool, label %land.lhs.true, label %if.end
land.lhs.true: ; preds = %for.body
%2 = load ptr, ptr %frame_ptr, align 8, !tbaa !6
%call = call i32 @get_data(ptr %2, ptr %frame)
%tobool1 = icmp ne i32 %call, 0
br i1 %tobool1, label %if.then, label %if.end
if.then: ; preds = %land.lhs.true
%3 = load ptr, ptr %frame, align 8, !tbaa !8
store ptr %3, ptr %frame_ptr, align 8, !tbaa !6
br label %if.end
if.end: ; preds = %if.then, %land.lhs.true, %for.body
br label %for.inc
for.inc: ; preds = %if.end
%4 = load i32, ptr %i, align 4, !tbaa !2
%inc = add nsw i32 %4, 1
store i32 %inc, ptr %i, align 4, !tbaa !2
br label %for.cond, !llvm.loop !10
for.end: ; preds = %for.cond.cleanup
%5 = load ptr, ptr %frame_ptr, align 8, !tbaa !6
%cmp2 = icmp eq ptr %5, null
%conv = zext i1 %cmp2 to i32
call void @llvm.lifetime.end.p0(i64 8, ptr %frame) #3
call void @llvm.lifetime.end.p0(i64 8, ptr %frame_ptr) #3
ret i32 %conv
}
; Function Attrs: argmemonly nounwind willreturn
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1
declare dso_local void @get_frame_ptr(ptr) #2
declare dso_local i32 @get_data(ptr, ptr) #2
; Function Attrs: argmemonly nounwind willreturn
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1
attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { argmemonly nounwind willreturn }
attributes #2 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #3 = { nounwind }
!llvm.module.flags = !{!0}
!llvm.ident = !{!1}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 12.0.0 (https://github.com/llvm/llvm-project.git 1b3c1c543269da36ae41ab84f646cf98d2e5b1e5)"}
!2 = !{!3, !3, i64 0}
!3 = !{!"int", !4, i64 0}
!4 = !{!"omnipotent char", !5, i64 0}
!5 = !{!"Simple C/C++ TBAA"}
!6 = !{!7, !7, i64 0}
!7 = !{!"any pointer", !4, i64 0}
!8 = !{!9, !7, i64 0}
!9 = !{!"", !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.unroll.disable"}
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