| Issue |
115574
|
| Summary |
[InstSimplify] wrong folding of pointer comparison `select (icmp eq ptr ...)`
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
bongjunj
|
Alive2 report: https://alive2.llvm.org/ce/z/aux2zY
```llvm
----------------------------------------
define ptr @smin_test8.2(ptr %a, ptr %b, ptr %c) {
#0:
%cmp1 = icmp eq ptr %a, %b
%umin1 = select i1 %cmp1, ptr %a, ptr %b
%cmp2 = icmp slt ptr %b, %c
%umin2 = select i1 %cmp2, ptr %b, ptr %c
%cmp3 = icmp ult ptr %umin2, %a
%umin3 = select i1 %cmp3, ptr %umin2, ptr %a
%cmp4 = icmp slt ptr %c, %umin3
%res = select i1 %cmp4, ptr %umin1, ptr %umin3
ret ptr %res
}
=>
define ptr @smin_test8.2(ptr %a, ptr %b, ptr %c) {
#0:
%cmp2 = icmp slt ptr %b, %c
%umin2 = select i1 %cmp2, ptr %b, ptr %c
%cmp3 = icmp ult ptr %umin2, %a
%umin3 = select i1 %cmp3, ptr %umin2, ptr %a
%cmp4 = icmp slt ptr %c, %umin3
%res = select i1 %cmp4, ptr %b, ptr %umin3
ret ptr %res
}
Transformation doesn't verify!
ERROR: Value mismatch
Example:
ptr %a = pointer(non-local, block_id=0, offset=1) / Address=#x1
ptr %b = pointer(non-local, block_id=1, offset=0) / Address=#x1
ptr %c = pointer(non-local, block_id=0, offset=-8) / Address=#x8
Source:
i1 %cmp1 = #x1 (1)
ptr %umin1 = pointer(non-local, block_id=0, offset=1) / Address=#x1
i1 %cmp2 = #x0 (0)
ptr %umin2 = pointer(non-local, block_id=0, offset=-8) / Address=#x8
i1 %cmp3 = #x0 (0)
ptr %umin3 = pointer(non-local, block_id=0, offset=1) / Address=#x1
i1 %cmp4 = #x1 (1)
ptr %res = pointer(non-local, block_id=0, offset=1) / Address=#x1
SOURCE MEMORY STATE
===================
NON-LOCAL BLOCKS:
Block 0 > size: 0 align: 1 alloc type: 0 alive: false address: 0
Block 1 > size: 1 align: 1 alloc type: 0 alive: true address: 1
Block 2 > size: 1 align: 1 alloc type: 0 alive: true address: 2
Block 3 > size: 3 align: 1 alloc type: 0 alive: true address: 8
Target:
i1 %cmp2 = #x0 (0)
ptr %umin2 = pointer(non-local, block_id=0, offset=-8) / Address=#x8
i1 %cmp3 = #x0 (0)
ptr %umin3 = pointer(non-local, block_id=0, offset=1) / Address=#x1
i1 %cmp4 = #x1 (1)
ptr %res = pointer(non-local, block_id=1, offset=0) / Address=#x1
Source value: pointer(non-local, block_id=0, offset=1) / Address=#x1
Target value: pointer(non-local, block_id=1, offset=0) / Address=#x1
Summary:
0 correct transformations
1 incorrect transformations
0 failed-to-prove transformations
0 Alive2 errors
```
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