forked from OSchip/llvm-project
49 lines
1.5 KiB
LLVM
49 lines
1.5 KiB
LLVM
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; RUN: llc -mtriple x86_64-- -stop-before peephole-opt -o %t.mir %s
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; RUN: llc -mtriple x86_64-- -run-pass none %t.mir -verify-machineinstrs -o - | FileCheck %s
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; Unreachable blocks in the machine instr representation are these
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; weird empty blocks with no successors.
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; The MIR printer used to not print empty lists of successors. However,
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; the MIR parser now treats non-printed list of successors as "please
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; guess it for me". As a result, the parser tries to guess the list of
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; successors and given the block is empty, just assumes it falls through
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; the next block.
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;
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; The following test case used to fail the verifier because the false
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; path ended up falling through split.true and now, the definition of
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; %v does not dominate all its uses.
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; Indeed, we go from the following CFG:
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; entry
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; / \
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; true (def) false
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; |
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; split.true (use)
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;
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; To this one:
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; entry
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; / \
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; true (def) false
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; | / <-- invalid edge
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; split.true (use)
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;
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; Because of the invalid edge, we get the "def does not
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; dominate all uses" error.
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;
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; CHECK-LABEL: name: foo
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; CHECK-LABEL: bb.{{[0-9]+}}.false:
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; CHECK-NEXT: successors:
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; CHECK-NOT: %bb.{{[0-9]+}}.split.true
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; CHECK-LABEL: bb.{{[0-9]+}}.split.true:
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define void @foo(i32* %bar) {
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br i1 undef, label %true, label %false
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true:
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%v = load i32, i32* %bar
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br label %split.true
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false:
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unreachable
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split.true:
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%vInc = add i32 %v, 1
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store i32 %vInc, i32* %bar
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ret void
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}
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