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Reduced test case from SLPVectorizer/X86/reduction-logical.ll's logical_and_icmp_clamp_extra_use_select:
SLPVectorizer/X86/reduction-logical.ll
logical_and_icmp_clamp_extra_use_select
define i1 @src(i32 %x3, i1 %d2) { %c2 = icmp slt i32 0, 0 %c3 = icmp slt i32 %x3, 0 %d0 = icmp sgt i32 1, 0 %d1 = icmp sgt i32 1, 0 %d22 = icmp sgt i32 1, 0 %d3 = icmp sgt i32 1, 0 %s2 = select i1 false, i1 false, i1 false %s3 = select i1 %s2, i1 %c3, i1 false %s4 = select i1 %s3, i1 %d0, i1 false %s5 = select i1 %s4, i1 %d1, i1 false %s6 = select i1 %s5, i1 %d2, i1 false %s7 = select i1 %s6, i1 %d3, i1 false ret i1 %s7 }
Alive2's output, showing that the SLP vectorizer changes the return value to poison because it flips the order of selects:
define i1 @src(i32 %x3, i1 %d2) { %0: %c2 = icmp slt i32 0, 0 %c3 = icmp slt i32 %x3, 0 %d0 = icmp sgt i32 1, 0 %d1 = icmp sgt i32 1, 0 %d22 = icmp sgt i32 1, 0 %d3 = icmp sgt i32 1, 0 %s2 = select i1 0, i1 0, i1 0 %s3 = select i1 %s2, i1 %c3, i1 0 %s4 = select i1 %s3, i1 %d0, i1 0 %s5 = select i1 %s4, i1 %d1, i1 0 %s6 = select i1 %s5, i1 %d2, i1 0 %s7 = select i1 %s6, i1 %d3, i1 0 ret i1 %s7 } => define i1 @src(i32 %x3, i1 %d2) { %0: %c2 = icmp slt i32 0, 0 %1 = insertelement <4 x i32> { 0, 0, 0, poison }, i32 %x3, i32 3 %2 = icmp sgt <4 x i32> { 1, 1, 1, 0 }, %1 %d22 = icmp sgt i32 1, 0 %s2 = select i1 0, i1 0, i1 0 %3 = freeze <4 x i1> %2 %4 = reduce_and <4 x i1> %3 %op.rdx = select i1 %d2, i1 %s2, i1 0 %op.rdx1 = select i1 %4, i1 %op.rdx, i1 0 ret i1 %op.rdx1 } Transformation doesn't verify! ERROR: Target is more poisonous than source Example: i32 %x3 = poison i1 %d2 = poison Source: i1 %c2 = #x0 (0) i1 %c3 = poison i1 %d0 = #x1 (1) i1 %d1 = #x1 (1) i1 %d22 = #x1 (1) i1 %d3 = #x1 (1) i1 %s2 = #x0 (0) i1 %s3 = #x0 (0) i1 %s4 = #x0 (0) i1 %s5 = #x0 (0) i1 %s6 = #x0 (0) i1 %s7 = #x0 (0) Target: i1 %c2 = #x0 (0) <4 x i32> %1 = < #x00000000 (0), #x00000000 (0), #x00000000 (0), poison > <4 x i1> %2 = < #x1 (1), #x1 (1), #x1 (1), poison > i1 %d22 = #x1 (1) i1 %s2 = #x0 (0) <4 x i1> %3 = < #x1 (1), #x1 (1), #x1 (1), #x1 (1) > i1 %4 = #x1 (1) i1 %op.rdx = poison i1 %op.rdx1 = poison Source value: #x0 (0) Target value: poison
cc @regehr @alexey-bataev @cilkplus @davemgreen @RKSimon
The text was updated successfully, but these errors were encountered:
Fixed in 982d9ef
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Reduced test case from
SLPVectorizer/X86/reduction-logical.ll
'slogical_and_icmp_clamp_extra_use_select
:Alive2's output, showing that the SLP vectorizer changes the return value to poison because it flips the order of selects:
cc @regehr @alexey-bataev @cilkplus @davemgreen @RKSimon
The text was updated successfully, but these errors were encountered: