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|
; RUN: llc < %s -march=bpf -mattr=+alu32 -verify-machineinstrs | FileCheck %s
;
; Source:
; struct __sk_buff {
; unsigned data;
; unsigned data_end;
; };
;
; ptr test(int flag, struct __sk_buff *skb)
; {
; ptr p;
;
; if (flag) {
; p = (ptr)(long)skb->data;
; __asm__ __volatile__("": : :"memory");
; } else {
; p = (ptr)(long)skb->data_end;
; __asm__ __volatile__("": : :"memory");
; }
;
; return p;
; }
; Compilation flag:
; clang -target bpf -O2 -S -emit-llvm t.c
%struct.__sk_buff = type { i32, i32 }
define dso_local ptr @test(i32 %flag, ptr nocapture readonly %skb) local_unnamed_addr {
entry:
%tobool = icmp eq i32 %flag, 0
br i1 %tobool, label %if.else, label %if.then
if.then:
%0 = load i32, ptr %skb, align 4
tail call void asm sideeffect "", "~{memory}"()
br label %if.end
if.else:
%data_end = getelementptr inbounds %struct.__sk_buff, ptr %skb, i64 0, i32 1
%1 = load i32, ptr %data_end, align 4
tail call void asm sideeffect "", "~{memory}"()
br label %if.end
if.end:
%p.0.in.in = phi i32 [ %0, %if.then ], [ %1, %if.else ]
%p.0.in = zext i32 %p.0.in.in to i64
%p.0 = inttoptr i64 %p.0.in to ptr
ret ptr %p.0
}
; CHECK: w0 = *(u32 *)(r2 + 0)
; CHECK: w0 = *(u32 *)(r2 + 4)
; CHECK-NOT: r[[#]] = w[[#]]
; CHECK: exit
|
