Track regmove instruction during binemit.

Register locations can change throughout an EBB. Make sure the
emit_inst() function considers this when encoding instructions and
update the register diversion tracker.

cranelift/filetests/isa/riscv/regmove.cton

@@ -0,0 +1,15 @@
+; Test tracking of register moves.
+test binemit
+isa riscv
+
+function %regmoves(i32 link [%x1]) -> i32 link [%x1] {
+ebb0(v9999: i32):
+    [-,%x10]            v1 = iconst.i32 1
+    [-,%x7]             v2 = iadd_imm v1, 1000          ; bin: 3e850393
+                        regmove v1, %x10 -> %x11        ; bin: 00050593
+    [-,%x7]             v3 = iadd_imm v1, 1000          ; bin: 3e858393
+                        regmove v1, %x11 -> %x10        ; bin: 00058513
+    [-,%x7]             v4 = iadd_imm v1, 1000          ; bin: 3e850393
+
+    return v9999
+}

cranelift/src/filetest/binemit.rs

@@ -10,6 +10,7 @@ use cretonne::binemit;
 use cretonne::ir;
 use cretonne::ir::entities::AnyEntity;
 use cretonne::isa::TargetIsa;
+use cretonne::regalloc::RegDiversions;
 use cton_reader::TestCommand;
 use filetest::subtest::{SubTest, Context, Result};
 use utils::{match_directive, pretty_error};
@@ -147,7 +148,9 @@ impl SubTest for TestBinEmit {
 
         // Now emit all instructions.
         let mut sink = TextSink::new(isa);
+        let mut divert = RegDiversions::new();
         for ebb in func.layout.ebbs() {
+            divert.clear();
             // Correct header offsets should have been computed by `relax_branches()`.
             assert_eq!(sink.offset,
                        func.offsets[ebb],
@@ -160,7 +163,7 @@ impl SubTest for TestBinEmit {
                 // Send legal encodings into the emitter.
                 if enc.is_legal() {
                     let before = sink.offset;
-                    isa.emit_inst(&func, inst, &mut sink);
+                    isa.emit_inst(&func, inst, &mut divert, &mut sink);
                     let emitted = sink.offset - before;
                     // Verify the encoding recipe sizes against the ISAs emit_inst implementation.
                     assert_eq!(emitted,

cranelift/src/filetest/compile.rs

@@ -52,7 +52,7 @@ impl SubTest for TestCompile {
         // Finally verify that the returned code size matches the emitted bytes.
         let mut sink = SizeSink { offset: 0 };
         binemit::emit_function(&comp_ctx.func,
-                               |func, inst, sink| isa.emit_inst(func, inst, sink),
+                               |func, inst, div, sink| isa.emit_inst(func, inst, div, sink),
                                &mut sink);
 
         if sink.offset != code_size {