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.
sdeleuze · Jul 18, 2017 · 2927878 · 2927878
1 parent 306ef20
commit 2927878
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diff --git a/filetests/isa/riscv/regmove.cton b/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
+}
diff --git a/lib/cretonne/meta/gen_binemit.py b/lib/cretonne/meta/gen_binemit.py
@@ -31,6 +31,9 @@ def gen_recipe(recipe, fmt):
     want_outs = any(isinstance(o, RegClass) or isinstance(o, Stack)
                     for o in recipe.outs)
 
+    # Regmove instructions get special treatment.
+    is_regmove = (recipe.format.name == 'RegMove')
+
     # First unpack the instruction.
     with fmt.indented(
             'if let InstructionData::{} {{'.format(iform.name),
@@ -46,7 +49,7 @@ def gen_recipe(recipe, fmt):
         fmt.outdented_line('} = func.dfg[inst] {')
 
         # Normalize to an `args` array.
-        if want_args:
+        if want_args and not is_regmove:
             if iform.has_value_list:
                 fmt.line('let args = args.as_slice(&func.dfg.value_lists);')
             elif nvops == 1:
@@ -56,11 +59,11 @@ def gen_recipe(recipe, fmt):
         # Don't bother with fixed registers.
         args = ''
         for i, arg in enumerate(recipe.ins):
-            if isinstance(arg, RegClass):
+            if isinstance(arg, RegClass) and not is_regmove:
                 v = 'in_reg{}'.format(i)
                 args += ', ' + v
                 fmt.line(
-                    'let {} = func.locations[args[{}]].unwrap_reg();'
+                    'let {} = divert.reg(args[{}], &func.locations);'
                     .format(v, i))
             elif isinstance(arg, Stack):
                 v = 'in_ss{}'.format(i)
@@ -93,6 +96,11 @@ def gen_recipe(recipe, fmt):
                         'let {} = func.locations[results[{}]].unwrap_stack();'
                         .format(v, i))
 
+        # Special handling for regmove instructions. Update the register
+        # diversion tracker.
+        if recipe.format.name == 'RegMove':
+            fmt.line('divert.regmove(arg, src, dst);')
+
         # Call hand-written code. If the recipe contains a code snippet, use
         # that. Otherwise cal a recipe function in the target ISA's binemit
         # module.
@@ -118,13 +126,15 @@ def gen_isa(isa, fmt):
         # No encoding recipes: Emit a stub.
         with fmt.indented(
                 'pub fn emit_inst<CS: CodeSink + ?Sized>'
-                '(func: &Function, inst: Inst, _sink: &mut CS) {', '}'):
+                '(func: &Function, inst: Inst, '
+                '_divert: &mut RegDiversions, _sink: &mut CS) {', '}'):
             fmt.line('bad_encoding(func, inst)')
     else:
         fmt.line('#[allow(unused_variables, unreachable_code)]')
         with fmt.indented(
                 'pub fn emit_inst<CS: CodeSink + ?Sized>'
-                '(func: &Function, inst: Inst, sink: &mut CS) {', '}'):
+                '(func: &Function, inst: Inst, '
+                'divert: &mut RegDiversions, sink: &mut CS) {', '}'):
             fmt.line('let bits = func.encodings[inst].bits();')
             with fmt.indented('match func.encodings[inst].recipe() {', '}'):
                 for i, recipe in enumerate(isa.all_recipes):

diff --git a/lib/cretonne/src/binemit/mod.rs b/lib/cretonne/src/binemit/mod.rs
@@ -10,6 +10,7 @@ pub use self::relaxation::relax_branches;
 pub use self::memorysink::{MemoryCodeSink, RelocSink};
 
 use ir::{Ebb, FuncRef, JumpTable, Function, Inst};
+use regalloc::RegDiversions;
 
 /// Offset in bytes from the beginning of the function.
 ///
@@ -64,13 +65,14 @@ pub fn bad_encoding(func: &Function, inst: Inst) -> ! {
 /// appropriate instruction emitter.
 pub fn emit_function<CS, EI>(func: &Function, emit_inst: EI, sink: &mut CS)
     where CS: CodeSink,
-          EI: Fn(&Function, Inst, &mut CS)
+          EI: Fn(&Function, Inst, &mut RegDiversions, &mut CS)
 {
+    let mut divert = RegDiversions::new();
     for ebb in func.layout.ebbs() {
+        divert.clear();
         assert_eq!(func.offsets[ebb], sink.offset());
         for inst in func.layout.ebb_insts(ebb) {
-            emit_inst(func, inst, sink);
+            emit_inst(func, inst, &mut divert, sink);
         }
-
     }
 }
diff --git a/lib/cretonne/src/isa/arm32/binemit.rs b/lib/cretonne/src/isa/arm32/binemit.rs
@@ -2,6 +2,7 @@
 
 use binemit::{CodeSink, bad_encoding};
 use ir::{Function, Inst};
+use regalloc::RegDiversions;
 
 include!(concat!(env!("OUT_DIR"), "/binemit-arm32.rs"));
 

diff --git a/lib/cretonne/src/isa/arm32/mod.rs b/lib/cretonne/src/isa/arm32/mod.rs
@@ -91,8 +91,12 @@ impl TargetIsa for Isa {
         abi::allocatable_registers(func)
     }
 
-    fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
-        binemit::emit_inst(func, inst, sink)
+    fn emit_inst(&self,
+                 func: &ir::Function,
+                 inst: ir::Inst,
+                 divert: &mut regalloc::RegDiversions,
+                 sink: &mut CodeSink) {
+        binemit::emit_inst(func, inst, divert, sink)
     }
 
     fn emit_function(&self, func: &ir::Function, sink: &mut MemoryCodeSink) {

diff --git a/lib/cretonne/src/isa/arm64/binemit.rs b/lib/cretonne/src/isa/arm64/binemit.rs
@@ -2,6 +2,7 @@
 
 use binemit::{CodeSink, bad_encoding};
 use ir::{Function, Inst};
+use regalloc::RegDiversions;
 
 include!(concat!(env!("OUT_DIR"), "/binemit-arm64.rs"));
 

diff --git a/lib/cretonne/src/isa/arm64/mod.rs b/lib/cretonne/src/isa/arm64/mod.rs
@@ -84,8 +84,12 @@ impl TargetIsa for Isa {
         abi::allocatable_registers(func)
     }
 
-    fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
-        binemit::emit_inst(func, inst, sink)
+    fn emit_inst(&self,
+                 func: &ir::Function,
+                 inst: ir::Inst,
+                 divert: &mut regalloc::RegDiversions,
+                 sink: &mut CodeSink) {
+        binemit::emit_inst(func, inst, divert, sink)
     }
 
     fn emit_function(&self, func: &ir::Function, sink: &mut MemoryCodeSink) {

diff --git a/lib/cretonne/src/isa/intel/binemit.rs b/lib/cretonne/src/isa/intel/binemit.rs
@@ -3,6 +3,7 @@
 use binemit::{CodeSink, Reloc, bad_encoding};
 use ir::{Function, Inst, InstructionData};
 use isa::RegUnit;
+use regalloc::RegDiversions;
 
 include!(concat!(env!("OUT_DIR"), "/binemit-intel.rs"));
 

diff --git a/lib/cretonne/src/isa/intel/mod.rs b/lib/cretonne/src/isa/intel/mod.rs
@@ -91,8 +91,12 @@ impl TargetIsa for Isa {
         abi::allocatable_registers(func, &self.shared_flags)
     }
 
-    fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
-        binemit::emit_inst(func, inst, sink)
+    fn emit_inst(&self,
+                 func: &ir::Function,
+                 inst: ir::Inst,
+                 divert: &mut regalloc::RegDiversions,
+                 sink: &mut CodeSink) {
+        binemit::emit_inst(func, inst, divert, sink)
     }
 
     fn emit_function(&self, func: &ir::Function, sink: &mut MemoryCodeSink) {

diff --git a/lib/cretonne/src/isa/mod.rs b/lib/cretonne/src/isa/mod.rs
@@ -215,7 +215,11 @@ pub trait TargetIsa {
     ///
     /// Note that this will call `put*` methods on the trait object via its vtable which is not the
     /// fastest way of emitting code.
-    fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut binemit::CodeSink);
+    fn emit_inst(&self,
+                 func: &ir::Function,
+                 inst: ir::Inst,
+                 divert: &mut regalloc::RegDiversions,
+                 sink: &mut binemit::CodeSink);
 
     /// Emit a whole function into memory.
     ///

diff --git a/lib/cretonne/src/isa/riscv/binemit.rs b/lib/cretonne/src/isa/riscv/binemit.rs
@@ -4,6 +4,7 @@ use binemit::{CodeSink, Reloc, bad_encoding};
 use ir::{Function, Inst, InstructionData};
 use isa::RegUnit;
 use predicates::is_signed_int;
+use regalloc::RegDiversions;
 
 include!(concat!(env!("OUT_DIR"), "/binemit-riscv.rs"));
 

diff --git a/lib/cretonne/src/isa/riscv/mod.rs b/lib/cretonne/src/isa/riscv/mod.rs
@@ -91,8 +91,12 @@ impl TargetIsa for Isa {
         abi::allocatable_registers(func, &self.isa_flags)
     }
 
-    fn emit_inst(&self, func: &ir::Function, inst: ir::Inst, sink: &mut CodeSink) {
-        binemit::emit_inst(func, inst, sink)
+    fn emit_inst(&self,
+                 func: &ir::Function,
+                 inst: ir::Inst,
+                 divert: &mut regalloc::RegDiversions,
+                 sink: &mut CodeSink) {
+        binemit::emit_inst(func, inst, divert, sink)
     }
 
     fn emit_function(&self, func: &ir::Function, sink: &mut MemoryCodeSink) {

diff --git a/src/filetest/binemit.rs b/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,

diff --git a/src/filetest/compile.rs b/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 {