github.com/tetratelabs/wazero@v1.7.3-0.20240513003603-48f702e154b5/internal/engine/wazevo/ssa/ssa_test.go (about)

     1  package ssa
     2  
     3  import "sort"
     4  
     5  // edgesCase is a map from BasicBlockID to its successors.
     6  type edgesCase map[BasicBlockID][]BasicBlockID
     7  
     8  // constructGraphFromEdges constructs a graph from edgesCase.
     9  // This comes in handy when we want to test the CFG related passes.
    10  func constructGraphFromEdges(edges edgesCase) (b *builder) {
    11  	b = NewBuilder().(*builder)
    12  
    13  	// Collect edges.
    14  	var maxID BasicBlockID
    15  	var pairs [][2]BasicBlockID
    16  	for fromID, toIDs := range edges {
    17  		if maxID < fromID {
    18  			maxID = fromID
    19  		}
    20  		for _, toID := range toIDs {
    21  			pairs = append(pairs, [2]BasicBlockID{fromID, toID})
    22  			if maxID < toID {
    23  				maxID = toID
    24  			}
    25  		}
    26  	}
    27  
    28  	// Allocate blocks.
    29  	blocks := make(map[BasicBlockID]*basicBlock, maxID+1)
    30  	for i := 0; i < int(maxID)+1; i++ {
    31  		blk := b.AllocateBasicBlock().(*basicBlock)
    32  		blocks[blk.id] = blk
    33  	}
    34  
    35  	// To have a consistent behavior in test, we sort the pairs by fromID.
    36  	sort.Slice(pairs, func(i, j int) bool {
    37  		xf, yf := pairs[i][0], pairs[j][0]
    38  		return xf < yf
    39  	})
    40  
    41  	// Add edges.
    42  	for _, p := range pairs {
    43  		from, to := blocks[p[0]], blocks[p[1]]
    44  		to.addPred(from, &Instruction{})
    45  	}
    46  	return
    47  }