Test Failure: Transforms/LoopIdiom/X86/logical-right-shift-until-zero.ll

Test source: git

Comments: LLVM PR51669

Log:

Source: <stdin>

----------------------------------------
define i8 @p0(i8 %val, i8 %start, i8 %extraoffset) {
%entry:
  br label %loop

%loop:
  %iv = phi i8 [ %start, %entry ], [ %iv.next, %loop ]
  %nbits = add nsw i8 %iv, %extraoffset
  %val.shifted = lshr i8 %val, %nbits
  %val.shifted.iszero = icmp eq i8 %val.shifted, 0
  %iv.next = add i8 %iv, 1
  call void @escape_inner(i8 %iv, i8 %nbits, i8 %val.shifted, i1 %val.shifted.iszero, i8 %iv.next)
  br i1 %val.shifted.iszero, label %end, label %loop

%end:
  %iv.res = phi i8 [ %iv, %loop ]
  %nbits.res = phi i8 [ %nbits, %loop ]
  %val.shifted.res = phi i8 [ %val.shifted, %loop ]
  %val.shifted.iszero.res = phi i1 [ %val.shifted.iszero, %loop ]
  %iv.next.res = phi i8 [ %iv.next, %loop ]
  call void @escape_outer(i8 %iv.res, i8 %nbits.res, i8 %val.shifted.res, i1 %val.shifted.iszero.res, i8 %iv.next.res)
  ret i8 %iv.res
}
=>
define i8 @p0(i8 %val, i8 %start, i8 %extraoffset) {
%entry:
  %val.numleadingzeros = ctlz i8 %val, 0
  %val.numactivebits = sub nsw nuw i8 8, %val.numleadingzeros
  %0 = sub i8 0, %extraoffset
  %val.numactivebits.offset = add nsw i8 %val.numactivebits, %0
  %iv.final = smax i8 %val.numactivebits.offset, %start
  %loop.backedgetakencount = sub nsw i8 %iv.final, %start
  %loop.tripcount = add nsw nuw i8 %loop.backedgetakencount, 1
  br label %loop

%loop:
  %loop.iv = phi i8 [ 0, %entry ], [ %loop.iv.next, %loop ]
  %loop.iv.next = add nsw nuw i8 %loop.iv, 1
  %loop.ivcheck = icmp eq i8 %loop.iv.next, %loop.tripcount
  %iv = add nsw i8 %loop.iv, %start
  %nbits = add nsw i8 %iv, %extraoffset
  %val.shifted = lshr i8 %val, %nbits
  %iv.next = add i8 %iv, 1
  call void @escape_inner(i8 %iv, i8 %nbits, i8 %val.shifted, i1 %loop.ivcheck, i8 %iv.next)
  br i1 %loop.ivcheck, label %end, label %loop

%end:
  %iv.res = phi i8 [ %iv.final, %loop ]
  %nbits.res = phi i8 [ %nbits, %loop ]
  %val.shifted.res = phi i8 [ %val.shifted, %loop ]
  %val.shifted.iszero.res = phi i1 [ %loop.ivcheck, %loop ]
  %iv.next.res = phi i8 [ %iv.next, %loop ]
  call void @escape_outer(i8 %iv.res, i8 %nbits.res, i8 %val.shifted.res, i1 %val.shifted.iszero.res, i8 %iv.next.res)
  ret i8 %iv.res
}
Transformation doesn't verify!
ERROR: Source is more defined than target

Example:
i8 %val = undef
i8 %start = #x7a (122)
i8 %extraoffset = #x86 (134, -122)

Source:
  >> Jump to %loop
i8 %iv = #x7a (122)
i8 %nbits = #x00 (0)
i8 %val.shifted = #x00 (0)	[based on undef value]
i1 %val.shifted.iszero = #x1 (1)
i8 %iv.next = #x7b (123)
void = UB triggered!

SOURCE MEMORY STATE
===================
NON-LOCAL BLOCKS:
Block 0 >	size: 0	align: 1	alloc type: 0
Block 1 >	size: 0	align: 1

Target:
i8 %val.numleadingzeros = #x05 (5)
i8 %val.numactivebits = #x03 (3)
i8 %0 = #x7a (122)
i8 %val.numactivebits.offset = #x7d (125)
i8 %iv.final = #x7d (125)
i8 %loop.backedgetakencount = #x03 (3)
i8 %loop.tripcount = #x04 (4)
  >> Jump to %loop
i8 %loop.iv = #x00 (0)
i8 %loop.iv.next = #x01 (1)
i1 %loop.ivcheck = #x0 (0)
i8 %iv = #x7a (122)
i8 %nbits = #x00 (0)
i8 %val.shifted = #x1e (30)
i8 %iv.next = #x7b (123)
void = UB triggered!



------------------- SMT STATS -------------------
Num queries: 4
Num invalid: 0
Num skips:   0
Num trivial: 22 (84.6%)
Num timeout: 0 (0.0%)
Num errors:  0 (0.0%)
Num SAT:     4 (100.0%)
Num UNSAT:   0 (0.0%)
Alive2: Transform doesn't verify; aborting!

stderr:

+ : 'RUN: at line 2'
+ /home/nlopes/alive2/build/opt-alive.sh -loop-idiom -mtriple=x86_64 -mcpu=core-avx2 -S
+ /home/nlopes/llvm/build/bin/FileCheck /home/nlopes/llvm/llvm/test/Transforms/LoopIdiom/X86/logical-right-shift-until-zero.ll

FileCheck error: '<stdin>' is empty.
FileCheck command line:  /home/nlopes/llvm/build/bin/FileCheck /home/nlopes/llvm/llvm/test/Transforms/LoopIdiom/X86/logical-right-shift-until-zero.ll

 

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