From ee22517d92c48eab9643b6fc8ce4dac2b7e95f57 Mon Sep 17 00:00:00 2001
From: Ficture Seven <FICTURE7@gmail.com>
Date: Wed, 5 Aug 2020 02:52:33 +0400
Subject: Improve branch operations (#1442)
* Add Compare instruction
* Add BranchIf instruction
* Use test when BranchIf & Compare against 0
* Propagate Compare into BranchIfTrue/False use
- Propagate Compare operations into their BranchIfTrue/False use and
turn these into a BranchIf.
- Clean up Comparison enum.
* Replace BranchIfTrue/False with BranchIf
* Use BranchIf in EmitPtPointerLoad
- Using BranchIf early instead of BranchIfTrue/False improves LCQ and
reduces the amount of work needed by the Optimizer.
EmitPtPointerLoader was a/the big producer of BranchIfTrue/False.
- Fix asserts firing when assembling BitwiseAnd because of type
mismatch in EmitStoreExclusive. This is harmless and should not
cause any diffs.
* Increment PPTC interval version
* Improve IRDumper for BranchIf & Compare
* Use BranchIf in EmitNativeCall
* Clean up
* Do not emit test when immediately preceded by and
---
ARMeilleure/CodeGen/X86/CodeGenerator.cs | 171 +++++++++++++++----------------
1 file changed, 83 insertions(+), 88 deletions(-)
(limited to 'ARMeilleure/CodeGen/X86/CodeGenerator.cs')
diff --git a/ARMeilleure/CodeGen/X86/CodeGenerator.cs b/ARMeilleure/CodeGen/X86/CodeGenerator.cs
index f04be52d..f2d4c462 100644
--- a/ARMeilleure/CodeGen/X86/CodeGenerator.cs
+++ b/ARMeilleure/CodeGen/X86/CodeGenerator.cs
@@ -33,24 +33,14 @@ namespace ARMeilleure.CodeGen.X86
Add(Instruction.BitwiseNot, GenerateBitwiseNot);
Add(Instruction.BitwiseOr, GenerateBitwiseOr);
Add(Instruction.Branch, GenerateBranch);
- Add(Instruction.BranchIfFalse, GenerateBranchIfFalse);
- Add(Instruction.BranchIfTrue, GenerateBranchIfTrue);
+ Add(Instruction.BranchIf, GenerateBranchIf);
Add(Instruction.ByteSwap, GenerateByteSwap);
Add(Instruction.Call, GenerateCall);
Add(Instruction.Clobber, GenerateClobber);
+ Add(Instruction.Compare, GenerateCompare);
Add(Instruction.CompareAndSwap, GenerateCompareAndSwap);
Add(Instruction.CompareAndSwap16, GenerateCompareAndSwap16);
Add(Instruction.CompareAndSwap8, GenerateCompareAndSwap8);
- Add(Instruction.CompareEqual, GenerateCompareEqual);
- Add(Instruction.CompareGreater, GenerateCompareGreater);
- Add(Instruction.CompareGreaterOrEqual, GenerateCompareGreaterOrEqual);
- Add(Instruction.CompareGreaterOrEqualUI, GenerateCompareGreaterOrEqualUI);
- Add(Instruction.CompareGreaterUI, GenerateCompareGreaterUI);
- Add(Instruction.CompareLess, GenerateCompareLess);
- Add(Instruction.CompareLessOrEqual, GenerateCompareLessOrEqual);
- Add(Instruction.CompareLessOrEqualUI, GenerateCompareLessOrEqualUI);
- Add(Instruction.CompareLessUI, GenerateCompareLessUI);
- Add(Instruction.CompareNotEqual, GenerateCompareNotEqual);
Add(Instruction.ConditionalSelect, GenerateConditionalSelect);
Add(Instruction.ConvertI64ToI32, GenerateConvertI64ToI32);
Add(Instruction.ConvertToFP, GenerateConvertToFP);
@@ -474,6 +464,8 @@ namespace ARMeilleure.CodeGen.X86
Debug.Assert(dest.Type.IsInteger());
+ // Note: GenerateCompareCommon makes the assumption that BitwiseAnd will emit only a single `and`
+ // instruction.
context.Assembler.And(dest, src2, dest.Type);
}
@@ -525,22 +517,17 @@ namespace ARMeilleure.CodeGen.X86
context.JumpTo(context.CurrBlock.Branch);
}
- private static void GenerateBranchIfFalse(CodeGenContext context, Operation operation)
+ private static void GenerateBranchIf(CodeGenContext context, Operation operation)
{
- Operand source = operation.GetSource(0);
-
- context.Assembler.Test(source, source, source.Type);
+ Operand comp = operation.GetSource(2);
- context.JumpTo(X86Condition.Equal, context.CurrBlock.Branch);
- }
+ Debug.Assert(comp.Kind == OperandKind.Constant);
- private static void GenerateBranchIfTrue(CodeGenContext context, Operation operation)
- {
- Operand source = operation.GetSource(0);
+ var cond = ((Comparison)comp.AsInt32()).ToX86Condition();
- context.Assembler.Test(source, source, source.Type);
+ GenerateCompareCommon(context, operation);
- context.JumpTo(X86Condition.NotEqual, context.CurrBlock.Branch);
+ context.JumpTo(cond, context.CurrBlock.Branch);
}
private static void GenerateByteSwap(CodeGenContext context, Operation operation)
@@ -566,6 +553,60 @@ namespace ARMeilleure.CodeGen.X86
// register allocator, we don't need to produce any code.
}
+ private static void GenerateCompare(CodeGenContext context, Operation operation)
+ {
+ Operand dest = operation.Destination;
+ Operand comp = operation.GetSource(2);
+
+ Debug.Assert(dest.Type == OperandType.I32);
+ Debug.Assert(comp.Kind == OperandKind.Constant);
+
+ var cond = ((Comparison)comp.AsInt32()).ToX86Condition();
+
+ GenerateCompareCommon(context, operation);
+
+ context.Assembler.Setcc(dest, cond);
+ context.Assembler.Movzx8(dest, dest, OperandType.I32);
+ }
+
+ private static void GenerateCompareCommon(CodeGenContext context, Operation operation)
+ {
+ Operand src1 = operation.GetSource(0);
+ Operand src2 = operation.GetSource(1);
+
+ EnsureSameType(src1, src2);
+
+ Debug.Assert(src1.Type.IsInteger());
+
+ if (src2.Kind == OperandKind.Constant && src2.Value == 0)
+ {
+ if (MatchOperation(operation.ListPrevious, Instruction.BitwiseAnd, src1.Type, src1.GetRegister()))
+ {
+ // Since the `test` and `and` instruction set the status flags in the same way, we can omit the
+ // `test r,r` instruction when it is immediately preceded by an `and r,*` instruction.
+ //
+ // For example:
+ //
+ // and eax, 0x3
+ // test eax, eax
+ // jz .L0
+ //
+ // =>
+ //
+ // and eax, 0x3
+ // jz .L0
+ }
+ else
+ {
+ context.Assembler.Test(src1, src1, src1.Type);
+ }
+ }
+ else
+ {
+ context.Assembler.Cmp(src1, src2, src1.Type);
+ }
+ }
+
private static void GenerateCompareAndSwap(CodeGenContext context, Operation operation)
{
Operand src1 = operation.GetSource(0);
@@ -615,71 +656,6 @@ namespace ARMeilleure.CodeGen.X86
context.Assembler.Cmpxchg8(memOp, src3);
}
- private static void GenerateCompareEqual(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.Equal);
- }
-
- private static void GenerateCompareGreater(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.Greater);
- }
-
- private static void GenerateCompareGreaterOrEqual(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.GreaterOrEqual);
- }
-
- private static void GenerateCompareGreaterOrEqualUI(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.AboveOrEqual);
- }
-
- private static void GenerateCompareGreaterUI(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.Above);
- }
-
- private static void GenerateCompareLess(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.Less);
- }
-
- private static void GenerateCompareLessOrEqual(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.LessOrEqual);
- }
-
- private static void GenerateCompareLessOrEqualUI(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.BelowOrEqual);
- }
-
- private static void GenerateCompareLessUI(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.Below);
- }
-
- private static void GenerateCompareNotEqual(CodeGenContext context, Operation operation)
- {
- GenerateCompare(context, operation, X86Condition.NotEqual);
- }
-
- private static void GenerateCompare(CodeGenContext context, Operation operation, X86Condition condition)
- {
- Operand dest = operation.Destination;
- Operand src1 = operation.GetSource(0);
- Operand src2 = operation.GetSource(1);
-
- EnsureSameType(src1, src2);
-
- Debug.Assert(dest.Type == OperandType.I32);
-
- context.Assembler.Cmp(src1, src2, src1.Type);
- context.Assembler.Setcc(dest, condition);
- context.Assembler.Movzx8(dest, dest, OperandType.I32);
- }
-
private static void GenerateConditionalSelect(CodeGenContext context, Operation operation)
{
Operand dest = operation.Destination;
@@ -1561,6 +1537,25 @@ namespace ARMeilleure.CodeGen.X86
context.Assembler.Pshufd(dest, dest, 0xfc);
}
+ private static bool MatchOperation(Node node, Instruction inst, OperandType destType, Register destReg)
+ {
+ if (!(node is Operation operation) || node.DestinationsCount == 0)
+ {
+ return false;
+ }
+
+ if (operation.Instruction != inst)
+ {
+ return false;
+ }
+
+ Operand dest = operation.Destination;
+
+ return dest.Kind == OperandKind.Register &&
+ dest.Type == destType &&
+ dest.GetRegister() == destReg;
+ }
+
[Conditional("DEBUG")]
private static void ValidateUnOp(Operand dest, Operand source)
{
--
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