Test Failure: Transforms/InstCombine/invert-variable-mask-in-masked-merge-vector.ll

Test source: git

Log:

Source: <stdin>
-- 1. ModuleToFunctionPassAdaptor
-- 1. PassManager<Function> : Skipping NOP
-- 2. InstCombinePass

----------------------------------------
define <2 x i4> @vector(<2 x i4> %x, <2 x i4> %y, <2 x i4> %m) {
%0:
  %im = xor <2 x i4> %m, { 15, 15 }
  %n0 = xor <2 x i4> %x, %y
  %n1 = and <2 x i4> %n0, %im
  %r = xor <2 x i4> %n1, %y
  ret <2 x i4> %r
}
Transformation seems to be correct! (syntactically equal)

-- 3. InstCombinePass

----------------------------------------
define <2 x i4> @vector(<2 x i4> %x, <2 x i4> %y, <2 x i4> %m) {
%0:
  %im = xor <2 x i4> %m, { 15, 15 }
  %n0 = xor <2 x i4> %x, %y
  %n1 = and <2 x i4> %n0, %im
  %r = xor <2 x i4> %n1, %y
  ret <2 x i4> %r
}
=>
define <2 x i4> @vector(<2 x i4> %x, <2 x i4> %y, <2 x i4> %m) {
%0:
  %n0 = xor <2 x i4> %x, %y
  %1 = and <2 x i4> %n0, %m
  %r = xor <2 x i4> %1, %x
  ret <2 x i4> %r
}
Transformation doesn't verify! (unsound)
ERROR: Target's return value is more undefined

Example:
<2 x i4> %x = < #xd (13, -3), undef >
<2 x i4> %y = < poison, #x2 (2) >
<2 x i4> %m = < poison, #xf (15, -1) >

Source:
<2 x i4> %im = < poison, #x0 (0) >
<2 x i4> %n0 = < poison, #x2 (2)	[based on undef value] >
<2 x i4> %n1 = < poison, #x0 (0) >
<2 x i4> %r = < poison, #x2 (2) >

Target:
<2 x i4> %n0 = < poison, #x2 (2) >
<2 x i4> %1 = < poison, #x2 (2) >
<2 x i4> %r = < poison, #x3 (3) >
Source value: < poison, #x2 (2) >
Target value: < poison, #x3 (3) >

Pass: InstCombinePass
Command line: '/home/nlopes/llvm/build/bin/opt' '-load=/home/nlopes/alive2/build/tv/tv.so' '-load-pass-plugin=/home/nlopes/alive2/build/tv/tv.so' '-tv-exit-on-error' '-passes=instcombine' '-S' '-tv-smt-to=20000' '-tv-report-dir=/home/nlopes/alive2/build/logs' '-tv-smt-stats'
Wrote bitcode to: "/home/nlopes/alive2/build/logs/in_3zNBAXla_lHW4.bc"


------------------- SMT STATS -------------------
Num queries: 5
Num invalid: 0
Num skips:   0
Num trivial: 15 (75.0%)
Num timeout: 0 (0.0%)
Num errors:  0 (0.0%)
Num SAT:     4 (80.0%)
Num UNSAT:   1 (20.0%)
Alive2: Transform doesn't verify; aborting!

stderr:

+ : 'RUN: at line 2'
+ /home/nlopes/alive2/build/opt-alive.sh -passes=instcombine -S
+ /bitbucket/nlopes/llvm/build/bin/FileCheck /bitbucket/nlopes/llvm/llvm/test/Transforms/InstCombine/invert-variable-mask-in-masked-merge-vector.ll

FileCheck error: '<stdin>' is empty.
FileCheck command line:  /bitbucket/nlopes/llvm/build/bin/FileCheck /bitbucket/nlopes/llvm/llvm/test/Transforms/InstCombine/invert-variable-mask-in-masked-merge-vector.ll

NOTE: This test would pass if undef didn't exist!

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