debug_regset_test.go

     1  // Copyright 2026 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package ssa
     6  
     7  import (
     8  	"testing"
     9  
    10  	"cmd/compile/internal/abt"
    11  	"cmd/compile/internal/ssa/ssaop"
    12  )
    13  
    14  // TestVarLocHighRegister checks that a variable in a register numbered 64 or
    15  // above (e.g. an arm64 P register) keeps its location.
    16  func TestVarLocHighRegister(t *testing.T) {
    17  	const lo, hi = 3, 70
    18  
    19  	loc := VarLoc{Registers: RegisterSet{}.AddReg(hi)}
    20  	if loc.absent() {
    21  		t.Fatalf("location in register %d is absent", hi)
    22  	}
    23  	if got := firstReg(loc.Registers); got != hi {
    24  		t.Errorf("firstReg = %d, want %d", got, hi)
    25  	}
    26  
    27  	both := VarLoc{Registers: loc.Registers.AddReg(lo)}
    28  	if got := both.intersect(loc); got.Registers != loc.Registers {
    29  		t.Errorf("intersect = %v, want %v", got.Registers, loc.Registers)
    30  	}
    31  	if !canMerge(loc, both) {
    32  		t.Errorf("canMerge(%v, %v) = false, want true", loc.Registers, both.Registers)
    33  	}
    34  	if canMerge(both, loc) {
    35  		t.Errorf("canMerge(%v, %v) = true, want false", both.Registers, loc.Registers)
    36  	}
    37  	if got := both.Registers.RemoveReg(ssaop.Register(hi)); got.HasReg(hi) || !got.HasReg(lo) {
    38  		t.Errorf("RemoveReg(%d) = %v", hi, got)
    39  	}
    40  
    41  	var live abt.T
    42  	live.Insert(0, &liveSlot{both})
    43  	state := StateAtPC{slots: make([]VarLoc, 1), registers: make([][]SlotID, hi+1)}
    44  	state.reset(live)
    45  	for _, r := range []int{lo, hi} {
    46  		if len(state.registers[r]) != 1 || state.registers[r][0] != 0 {
    47  			t.Errorf("registers[%d] = %v, want [0]", r, state.registers[r])
    48  		}
    49  	}
    50  }
    51
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