diff options
Diffstat (limited to 'contrib/llvm/patches/patch-r275633-llvm-r223171-fix-vectorizer.diff')
| -rw-r--r-- | contrib/llvm/patches/patch-r275633-llvm-r223171-fix-vectorizer.diff | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/contrib/llvm/patches/patch-r275633-llvm-r223171-fix-vectorizer.diff b/contrib/llvm/patches/patch-r275633-llvm-r223171-fix-vectorizer.diff new file mode 100644 index 0000000..a0b4e1f --- /dev/null +++ b/contrib/llvm/patches/patch-r275633-llvm-r223171-fix-vectorizer.diff @@ -0,0 +1,529 @@ +Pull in r223170 from upstream llvm trunk (by Michael Zolotukhin): + + Apply loop-rotate to several vectorizer tests. + + Such loops shouldn't be vectorized due to the loops form. + After applying loop-rotate (+simplifycfg) the tests again start to check + what they are intended to check. + +Pull in r223171 from upstream llvm trunk (by Michael Zolotukhin): + + PR21302. Vectorize only bottom-tested loops. + + rdar://problem/18886083 + +This fixes a bug in the llvm vectorizer, which could sometimes cause +vectorized loops to perform an additional iteration, leading to possible +buffer overruns. Symptoms of this, which are usually segfaults, were +first noticed when building gcc ports, here: + +https://lists.freebsd.org/pipermail/freebsd-ports/2014-September/095466.html +https://lists.freebsd.org/pipermail/freebsd-toolchain/2014-September/001211.html + +Introduced here: http://svnweb.freebsd.org/changeset/base/275633 + +Index: lib/Transforms/Vectorize/LoopVectorize.cpp +=================================================================== +--- lib/Transforms/Vectorize/LoopVectorize.cpp ++++ lib/Transforms/Vectorize/LoopVectorize.cpp +@@ -2864,6 +2864,14 @@ bool LoopVectorizationLegality::canVectorize() { + if (!TheLoop->getExitingBlock()) + return false; + ++ // We only handle bottom-tested loops, i.e. loop in which the condition is ++ // checked at the end of each iteration. With that we can assume that all ++ // instructions in the loop are executed the same number of times. ++ if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) { ++ DEBUG(dbgs() << "LV: loop control flow is not understood by vectorizer\n"); ++ return false; ++ } ++ + // We need to have a loop header. + DEBUG(dbgs() << "LV: Found a loop: " << + TheLoop->getHeader()->getName() << '\n'); +Index: test/Transforms/LoopVectorize/loop-form.ll +=================================================================== +--- test/Transforms/LoopVectorize/loop-form.ll ++++ test/Transforms/LoopVectorize/loop-form.ll +@@ -0,0 +1,31 @@ ++; RUN: opt -S -loop-vectorize < %s | FileCheck %s ++target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128" ++ ++; Check that we vectorize only bottom-tested loops. ++; This is a reduced testcase from PR21302. ++; ++; rdar://problem/18886083 ++ ++%struct.X = type { i32, i16 } ++; CHECK-LABEL: @foo( ++; CHECK-NOT: vector.body ++ ++define void @foo(i32 %n) { ++entry: ++ br label %for.cond ++ ++for.cond: ++ %i = phi i32 [ 0, %entry ], [ %inc, %for.body ] ++ %cmp = icmp slt i32 %i, %n ++ br i1 %cmp, label %for.body, label %if.end ++ ++for.body: ++ %iprom = sext i32 %i to i64 ++ %b = getelementptr inbounds %struct.X* undef, i64 %iprom, i32 1 ++ store i16 0, i16* %b, align 4 ++ %inc = add nsw i32 %i, 1 ++ br label %for.cond ++ ++if.end: ++ ret void ++} +Index: test/Transforms/LoopVectorize/runtime-check-address-space.ll +=================================================================== +--- test/Transforms/LoopVectorize/runtime-check-address-space.ll ++++ test/Transforms/LoopVectorize/runtime-check-address-space.ll +@@ -31,25 +31,23 @@ define void @foo(i32 addrspace(1)* %a, i32 addrspa + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %idxprom + %0 = load i32 addrspace(1)* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %idxprom1 + store i32 %mul, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -60,25 +58,23 @@ define void @bar0(i32* %a, i32 addrspace(1)* %b, i + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %idxprom + %0 = load i32 addrspace(1)* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds i32* %a, i64 %idxprom1 + store i32 %mul, i32* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -89,25 +85,23 @@ define void @bar1(i32 addrspace(1)* %a, i32* %b, i + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds i32* %b, i64 %idxprom + %0 = load i32* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %idxprom1 + store i32 %mul, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -119,25 +113,23 @@ define void @bar2(i32* noalias %a, i32 addrspace(1 + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %idxprom + %0 = load i32 addrspace(1)* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds i32* %a, i64 %idxprom1 + store i32 %mul, i32* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -149,25 +141,23 @@ define void @arst0(i32* %b, i32 %n) #0 { + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds i32* %b, i64 %idxprom + %0 = load i32* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds [1024 x i32] addrspace(1)* @g_as1, i64 0, i64 %idxprom1 + store i32 %mul, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -180,25 +170,23 @@ define void @arst1(i32* %b, i32 %n) #0 { + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds [1024 x i32] addrspace(1)* @g_as1, i64 0, i64 %idxprom + %0 = load i32 addrspace(1)* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds i32* %b, i64 %idxprom1 + store i32 %mul, i32* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +@@ -210,25 +198,23 @@ define void @aoeu(i32 %n) #0 { + ; CHECK: ret + + entry: +- br label %for.cond ++ %cmp1 = icmp slt i32 0, %n ++ br i1 %cmp1, label %for.body, label %for.end + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp slt i32 %i.0, %n +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %idxprom = sext i32 %i.0 to i64 ++for.body: ; preds = %entry, %for.body ++ %i.02 = phi i32 [ %inc, %for.body ], [ 0, %entry ] ++ %idxprom = sext i32 %i.02 to i64 + %arrayidx = getelementptr inbounds [1024 x i32] addrspace(2)* @q_as2, i64 0, i64 %idxprom + %0 = load i32 addrspace(2)* %arrayidx, align 4 + %mul = mul nsw i32 %0, 3 +- %idxprom1 = sext i32 %i.0 to i64 ++ %idxprom1 = sext i32 %i.02 to i64 + %arrayidx2 = getelementptr inbounds [1024 x i32] addrspace(1)* @g_as1, i64 0, i64 %idxprom1 + store i32 %mul, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add nsw i32 %i.0, 1 +- br label %for.cond ++ %inc = add nsw i32 %i.02, 1 ++ %cmp = icmp slt i32 %inc, %n ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body, %entry + ret void + } + +Index: test/Transforms/LoopVectorize/runtime-check-readonly-address-space.ll +=================================================================== +--- test/Transforms/LoopVectorize/runtime-check-readonly-address-space.ll ++++ test/Transforms/LoopVectorize/runtime-check-readonly-address-space.ll +@@ -8,26 +8,24 @@ define void @add_ints_1_1_1(i32 addrspace(1)* %a, + ; CHECK-LABEL: @add_ints_1_1_1( + ; CHECK: <4 x i32> + ; CHECK: ret ++ + entry: +- br label %for.cond ++ br label %for.body + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp ult i64 %i.0, 200 +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.0 ++for.body: ; preds = %entry, %for.body ++ %i.01 = phi i64 [ 0, %entry ], [ %inc, %for.body ] ++ %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.01 + %0 = load i32 addrspace(1)* %arrayidx, align 4 +- %arrayidx1 = getelementptr inbounds i32 addrspace(1)* %c, i64 %i.0 ++ %arrayidx1 = getelementptr inbounds i32 addrspace(1)* %c, i64 %i.01 + %1 = load i32 addrspace(1)* %arrayidx1, align 4 + %add = add nsw i32 %0, %1 +- %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %i.0 ++ %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %i.01 + store i32 %add, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add i64 %i.0, 1 +- br label %for.cond ++ %inc = add i64 %i.01, 1 ++ %cmp = icmp ult i64 %inc, 200 ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body + ret void + } + +@@ -35,26 +33,24 @@ define void @add_ints_as_1_0_0(i32 addrspace(1)* % + ; CHECK-LABEL: @add_ints_as_1_0_0( + ; CHECK-NOT: <4 x i32> + ; CHECK: ret ++ + entry: +- br label %for.cond ++ br label %for.body + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp ult i64 %i.0, 200 +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %arrayidx = getelementptr inbounds i32* %b, i64 %i.0 ++for.body: ; preds = %entry, %for.body ++ %i.01 = phi i64 [ 0, %entry ], [ %inc, %for.body ] ++ %arrayidx = getelementptr inbounds i32* %b, i64 %i.01 + %0 = load i32* %arrayidx, align 4 +- %arrayidx1 = getelementptr inbounds i32* %c, i64 %i.0 ++ %arrayidx1 = getelementptr inbounds i32* %c, i64 %i.01 + %1 = load i32* %arrayidx1, align 4 + %add = add nsw i32 %0, %1 +- %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %i.0 ++ %arrayidx2 = getelementptr inbounds i32 addrspace(1)* %a, i64 %i.01 + store i32 %add, i32 addrspace(1)* %arrayidx2, align 4 +- %inc = add i64 %i.0, 1 +- br label %for.cond ++ %inc = add i64 %i.01, 1 ++ %cmp = icmp ult i64 %inc, 200 ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body + ret void + } + +@@ -62,26 +58,24 @@ define void @add_ints_as_0_1_0(i32* %a, i32 addrsp + ; CHECK-LABEL: @add_ints_as_0_1_0( + ; CHECK-NOT: <4 x i32> + ; CHECK: ret ++ + entry: +- br label %for.cond ++ br label %for.body + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp ult i64 %i.0, 200 +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.0 ++for.body: ; preds = %entry, %for.body ++ %i.01 = phi i64 [ 0, %entry ], [ %inc, %for.body ] ++ %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.01 + %0 = load i32 addrspace(1)* %arrayidx, align 4 +- %arrayidx1 = getelementptr inbounds i32* %c, i64 %i.0 ++ %arrayidx1 = getelementptr inbounds i32* %c, i64 %i.01 + %1 = load i32* %arrayidx1, align 4 + %add = add nsw i32 %0, %1 +- %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.0 ++ %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.01 + store i32 %add, i32* %arrayidx2, align 4 +- %inc = add i64 %i.0, 1 +- br label %for.cond ++ %inc = add i64 %i.01, 1 ++ %cmp = icmp ult i64 %inc, 200 ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body + ret void + } + +@@ -89,26 +83,24 @@ define void @add_ints_as_0_1_1(i32* %a, i32 addrsp + ; CHECK-LABEL: @add_ints_as_0_1_1( + ; CHECK-NOT: <4 x i32> + ; CHECK: ret ++ + entry: +- br label %for.cond ++ br label %for.body + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp ult i64 %i.0, 200 +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.0 ++for.body: ; preds = %entry, %for.body ++ %i.01 = phi i64 [ 0, %entry ], [ %inc, %for.body ] ++ %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.01 + %0 = load i32 addrspace(1)* %arrayidx, align 4 +- %arrayidx1 = getelementptr inbounds i32 addrspace(1)* %c, i64 %i.0 ++ %arrayidx1 = getelementptr inbounds i32 addrspace(1)* %c, i64 %i.01 + %1 = load i32 addrspace(1)* %arrayidx1, align 4 + %add = add nsw i32 %0, %1 +- %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.0 ++ %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.01 + store i32 %add, i32* %arrayidx2, align 4 +- %inc = add i64 %i.0, 1 +- br label %for.cond ++ %inc = add i64 %i.01, 1 ++ %cmp = icmp ult i64 %inc, 200 ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body + ret void + } + +@@ -116,26 +108,24 @@ define void @add_ints_as_0_1_2(i32* %a, i32 addrsp + ; CHECK-LABEL: @add_ints_as_0_1_2( + ; CHECK-NOT: <4 x i32> + ; CHECK: ret ++ + entry: +- br label %for.cond ++ br label %for.body + +-for.cond: ; preds = %for.body, %entry +- %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.body ] +- %cmp = icmp ult i64 %i.0, 200 +- br i1 %cmp, label %for.body, label %for.end +- +-for.body: ; preds = %for.cond +- %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.0 ++for.body: ; preds = %entry, %for.body ++ %i.01 = phi i64 [ 0, %entry ], [ %inc, %for.body ] ++ %arrayidx = getelementptr inbounds i32 addrspace(1)* %b, i64 %i.01 + %0 = load i32 addrspace(1)* %arrayidx, align 4 +- %arrayidx1 = getelementptr inbounds i32 addrspace(2)* %c, i64 %i.0 ++ %arrayidx1 = getelementptr inbounds i32 addrspace(2)* %c, i64 %i.01 + %1 = load i32 addrspace(2)* %arrayidx1, align 4 + %add = add nsw i32 %0, %1 +- %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.0 ++ %arrayidx2 = getelementptr inbounds i32* %a, i64 %i.01 + store i32 %add, i32* %arrayidx2, align 4 +- %inc = add i64 %i.0, 1 +- br label %for.cond ++ %inc = add i64 %i.01, 1 ++ %cmp = icmp ult i64 %inc, 200 ++ br i1 %cmp, label %for.body, label %for.end + +-for.end: ; preds = %for.cond ++for.end: ; preds = %for.body + ret void + } + |
