Llvm phi指令并非主导所有用途

我有llvm IR功能 当我尝试将其转换为.bc时，llvm as显示了很多错误。 例如：

Instruction does not dominate all uses!
     %rightBoundary.1.i = phi i32 [ %dec.i, %while.cond1.i ], [ %rightBoundary.046.i, %while.cond1.preheader.i ]
      %rightBoundary.046.i = phi i32 [ %rightBoundary.1.i, %while.end17.i ], [ %endIndex, %bNew_block ]

我在llvm ir代码中做错了什么？我想在llvm ir代码中插入一些不透明谓词

; Function Attrs: nounwind uwtable
define void @_Z9ArraySortPiii(i32* %array, i32 %startIndex, i32 %endIndex) #3 {
entry:
  %cmp18 = icmp sgt i32 %endIndex, %startIndex
  br i1 %cmp18, label %while.cond1.preheader.i.preheader, label %if.end

while.cond1.preheader.i.preheader:                ; preds = %_Z10SplitArrayPiiii.exit, %entry
  %idxprom16.pn.in = phi i32 [ %inc.i, %_Z10SplitArrayPiiii.exit ], [ %startIndex, %entry ]
  %0 = alloca i32
  store i32 12222, i32* %0
  %1 = load i32* %0
  %predicate_cmp = icmp eq i32 0, %1
  br i1 %predicate_cmp, label %bNew_block, label %while.end.i

bNew_block:                                       ; preds = %while.cond1.preheader.i.preheader
  %idxprom16.pn = sext i32 %idxprom16.pn.in to i64
  %.in = getelementptr inbounds i32* %array, i64 %idxprom16.pn
  %2 = load i32* %.in, align 4
  br label %while.cond1.preheader.i

while.cond1.preheader.i:                          ; preds = %while.end17.i, %bNew_block
  %rightBoundary.046.i = phi i32 [ %rightBoundary.1.i, %while.end17.i ], [ %endIndex, %bNew_block ]
  %leftBoundary.045.i = phi i32 [ %leftBoundary.1.i, %while.end17.i ], [ %idxprom16.pn.in, %bNew_block ]
  %3 = sext i32 %rightBoundary.046.i to i64
  br label %while.cond1.i

while.cond1.i:                                    ; preds = %while.cond1.i, %while.cond1.preheader.i
  %indvars.iv.i = phi i64 [ %indvars.iv.next.i, %while.cond1.i ], [ %3, %while.cond1.preheader.i ]
  %rightBoundary.1.i = phi i32 [ %dec.i, %while.cond1.i ], [ %rightBoundary.046.i, %while.cond1.preheader.i ]
  %arrayidx.i = getelementptr inbounds i32* %array, i64 %indvars.iv.i
  %4 = load i32* %arrayidx.i, align 4, !tbaa !0
  %5 = trunc i64 %indvars.iv.i to i32
  %cmp2.i = icmp sgt i32 %4, %2
  %cmp3.i = icmp sgt i32 %5, %leftBoundary.045.i
  %or.cond.i = and i1 %cmp2.i, %cmp3.i
  %indvars.iv.next.i = add i64 %indvars.iv.i, -1
  %dec.i = add nsw i32 %rightBoundary.1.i, -1
  br i1 %or.cond.i, label %while.cond1.i, label %while.end.i

while.end.i:                                      ; preds = %while.cond1.preheader.i.preheader, %while.cond1.i
  %idxprom5.i = sext i32 %leftBoundary.045.i to i64
  %arrayidx6.i = getelementptr inbounds i32* %array, i64 %idxprom5.i
  %6 = load i32* %arrayidx6.i, align 4, !tbaa !0
  store i32 %4, i32* %arrayidx6.i, align 4, !tbaa !0
  store i32 %6, i32* %arrayidx.i, align 4, !tbaa !0
  br label %while.cond9.i

while.cond9.i:                                    ; preds = %while.cond9.i, %while.end.i
  %indvars.iv48.i = phi i64 [ %indvars.iv.next49.i, %while.cond9.i ], [ %idxprom5.i, %while.end.i ]
  %leftBoundary.1.i = phi i32 [ %inc.i, %while.cond9.i ], [ %leftBoundary.045.i, %while.end.i ]
  %arrayidx11.i = getelementptr inbounds i32* %array, i64 %indvars.iv48.i
  %7 = load i32* %arrayidx11.i, align 4, !tbaa !0
  %8 = trunc i64 %indvars.iv48.i to i32
  %cmp12.i = icmp sle i32 %7, %2
  %cmp14.i = icmp slt i32 %8, %rightBoundary.1.i
  %inc.i = add nsw i32 %leftBoundary.1.i, 1
  %indvars.iv.next49.i = add i64 %indvars.iv48.i, 1
  %or.cond42.i = and i1 %cmp12.i, %cmp14.i
  br i1 %or.cond42.i, label %while.cond9.i, label %while.end17.i

while.end17.i:                                    ; preds = %while.cond9.i
  store i32 %6, i32* %arrayidx11.i, align 4, !tbaa !0
  store i32 %7, i32* %arrayidx.i, align 4, !tbaa !0
  %cmp.i = icmp slt i32 %leftBoundary.1.i, %rightBoundary.1.i
  br i1 %cmp.i, label %while.cond1.preheader.i, label %_Z10SplitArrayPiiii.exit

_Z10SplitArrayPiiii.exit:                         ; preds = %while.end17.i
  %idxprom1 = sext i32 %leftBoundary.1.i to i64
  %arrayidx2 = getelementptr inbounds i32* %array, i64 %idxprom1
  store i32 %2, i32* %arrayidx2, align 4, !tbaa !0
  %sub = add nsw i32 %leftBoundary.1.i, -1
  tail call void @_Z9ArraySortPiii(i32* %array, i32 %idxprom16.pn.in, i32 %sub)
  %cmp = icmp slt i32 %inc.i, %endIndex
  br i1 %cmp, label %while.cond1.preheader.i.preheader, label %if.end

if.end:                                           ; preds = %_Z10SplitArrayPiiii.exit, %entry
  ret void
}

---

指令并非支配所有用途

 %rightBoundary.1.i = phi i32 [ %dec.i, %while.cond1.i ], [ %rightBoundary.046.i, %while.cond1.preheader.i ]
  %rightBoundary.046.i = phi i32 [ %rightBoundary.1.i, %while.end17.i ], [ %endIndex, %bNew_block ]
Instruction does not dominate all uses!
  %2 = load i32* %.in, align 4
  %cmp2.i = icmp sgt i32 %4, %2
Instruction does not dominate all uses!
  %leftBoundary.045.i = phi i32 [ %leftBoundary.1.i, %while.end17.i ], [ %idxprom16.pn.in, %bNew_block ]
  %idxprom5.i = sext i32 %leftBoundary.045.i to i64
Instruction does not dominate all uses!
  %4 = load i32* %arrayidx.i, align 4, !tbaa !0
  store i32 %4, i32* %arrayidx6.i, align 4, !tbaa !0
Instruction does not dominate all uses!
  %arrayidx.i = getelementptr inbounds i32* %array, i64 %indvars.iv.i
  store i32 %6, i32* %arrayidx.i, align 4, !tbaa !0
Instruction does not dominate all uses!
  %leftBoundary.045.i = phi i32 [ %leftBoundary.1.i, %while.end17.i ], [ %idxprom16.pn.in, %bNew_block ]
  %leftBoundary.1.i = phi i32 [ %inc.i, %while.cond9.i ], [ %leftBoundary.045.i, %while.end.i ]
Instruction does not dominate all uses!
  %2 = load i32* %.in, align 4
  %cmp12.i = icmp sle i32 %7, %2
Instruction does not dominate all uses!
  %rightBoundary.1.i = phi i32 [ %dec.i, %while.cond1.i ], [ %rightBoundary.046.i, %while.cond1.preheader.i ]
  %cmp14.i = icmp slt i32 %8, %rightBoundary.1.i
Instruction does not dominate all uses!
  %arrayidx.i = getelementptr inbounds i32* %array, i64 %indvars.iv.i
  store i32 %7, i32* %arrayidx.i, align 4, !tbaa !0
Instruction does not dominate all uses!
  %rightBoundary.1.i = phi i32 [ %dec.i, %while.cond1.i ], [ %rightBoundary.046.i, %while.cond1.preheader.i ]
  %cmp.i = icmp slt i32 %leftBoundary.1.i, %rightBoundary.1.i
Instruction does not dominate all uses!
  %2 = load i32* %.in, align 4
  store i32 %2, i32* %arrayidx2, align 4, !tbaa !0

---

指令并不是支配所有用途，这意味着您使用的寄存器来自可能尚未执行的块

---

在这种情况下，您似乎正在某个块中使用由phi指令分配的寄存器，该块可以在不执行phi指令的情况下访问

您能给我举个例子吗？我不完全理解：在这种情况下，您似乎在某个块中使用phi指令分配给的寄存器，而不执行phi指令define void@fooi1%a{entry:br i1%a，label%one，label%exit one:%b=xor i1%a，%a br label%exit:%c=xor i1%b，%b ret void}%c将生成支配者错误，因为它使用%b，但可能从未创建过%b