From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:02:58 +0200
Subject: Adding upstream version 1.64.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../rustc_codegen_cranelift/src/optimize/mod.rs    | 20 +++++++
 .../src/optimize/peephole.rs                       | 67 ++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 compiler/rustc_codegen_cranelift/src/optimize/mod.rs
 create mode 100644 compiler/rustc_codegen_cranelift/src/optimize/peephole.rs

(limited to 'compiler/rustc_codegen_cranelift/src/optimize')

diff --git a/compiler/rustc_codegen_cranelift/src/optimize/mod.rs b/compiler/rustc_codegen_cranelift/src/optimize/mod.rs
new file mode 100644
index 000000000..d1f89adb3
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/src/optimize/mod.rs
@@ -0,0 +1,20 @@
+//! Various optimizations specific to cg_clif
+
+use cranelift_codegen::isa::TargetIsa;
+
+use crate::prelude::*;
+
+pub(crate) mod peephole;
+
+pub(crate) fn optimize_function<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    isa: &dyn TargetIsa,
+    instance: Instance<'tcx>,
+    ctx: &mut Context,
+    clif_comments: &mut crate::pretty_clif::CommentWriter,
+) {
+    // FIXME classify optimizations over opt levels once we have more
+
+    crate::pretty_clif::write_clif_file(tcx, "preopt", isa, instance, &ctx.func, &*clif_comments);
+    crate::base::verify_func(tcx, &*clif_comments, &ctx.func);
+}
diff --git a/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs b/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs
new file mode 100644
index 000000000..d637b4d89
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/src/optimize/peephole.rs
@@ -0,0 +1,67 @@
+//! Peephole optimizations that can be performed while creating clif ir.
+
+use cranelift_codegen::ir::{condcodes::IntCC, InstructionData, Opcode, Value, ValueDef};
+use cranelift_frontend::FunctionBuilder;
+
+/// If the given value was produced by a `bint` instruction, return it's input, otherwise return the
+/// given value.
+pub(crate) fn maybe_unwrap_bint(bcx: &mut FunctionBuilder<'_>, arg: Value) -> Value {
+    if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
+        match bcx.func.dfg[arg_inst] {
+            InstructionData::Unary { opcode: Opcode::Bint, arg } => arg,
+            _ => arg,
+        }
+    } else {
+        arg
+    }
+}
+
+/// If the given value was produced by the lowering of `Rvalue::Not` return the input and true,
+/// otherwise return the given value and false.
+pub(crate) fn maybe_unwrap_bool_not(bcx: &mut FunctionBuilder<'_>, arg: Value) -> (Value, bool) {
+    if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
+        match bcx.func.dfg[arg_inst] {
+            // This is the lowering of `Rvalue::Not`
+            InstructionData::IntCompareImm {
+                opcode: Opcode::IcmpImm,
+                cond: IntCC::Equal,
+                arg,
+                imm,
+            } if imm.bits() == 0 => (arg, true),
+            _ => (arg, false),
+        }
+    } else {
+        (arg, false)
+    }
+}
+
+/// Returns whether the branch is statically known to be taken or `None` if it isn't statically known.
+pub(crate) fn maybe_known_branch_taken(
+    bcx: &FunctionBuilder<'_>,
+    arg: Value,
+    test_zero: bool,
+) -> Option<bool> {
+    let arg_inst = if let ValueDef::Result(arg_inst, 0) = bcx.func.dfg.value_def(arg) {
+        arg_inst
+    } else {
+        return None;
+    };
+
+    match bcx.func.dfg[arg_inst] {
+        InstructionData::UnaryBool { opcode: Opcode::Bconst, imm } => {
+            if test_zero {
+                Some(!imm)
+            } else {
+                Some(imm)
+            }
+        }
+        InstructionData::UnaryImm { opcode: Opcode::Iconst, imm } => {
+            if test_zero {
+                Some(imm.bits() == 0)
+            } else {
+                Some(imm.bits() != 0)
+            }
+        }
+        _ => None,
+    }
+}
-- 
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