From d6266a7666c22b4a64bbc9252e4ad080f5950d01 Mon Sep 17 00:00:00 2001
From: lcnr/Bastian Kauschke <bastian_kauschke@hotmail.de>
Date: Mon, 3 Jun 2019 12:59:17 +0200
Subject: [PATCH] add support for unchecked math

---
 src/librustc_codegen_llvm/builder.rs       |  6 +++++
 src/librustc_codegen_llvm/llvm/ffi.rs      | 30 ++++++++++++++++++++++
 src/librustc_codegen_ssa/traits/builder.rs |  6 +++++
 3 files changed, 42 insertions(+)

diff --git a/src/librustc_codegen_llvm/builder.rs b/src/librustc_codegen_llvm/builder.rs
index f37fd0cb8338..102e9e38612e 100644
--- a/src/librustc_codegen_llvm/builder.rs
+++ b/src/librustc_codegen_llvm/builder.rs
@@ -265,6 +265,12 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         neg(x) => LLVMBuildNeg,
         fneg(x) => LLVMBuildFNeg,
         not(x) => LLVMBuildNot,
+        unchecked_sadd(x, y) => LLVMBuildNSWAdd,
+        unchecked_uadd(x, y) => LLVMBuildNUWAdd,
+        unchecked_ssub(x, y) => LLVMBuildNSWSub,
+        unchecked_usub(x, y) => LLVMBuildNUWSub,
+        unchecked_smul(x, y) => LLVMBuildNSWMul,
+        unchecked_umul(x, y) => LLVMBuildNUWMul,
     }
 
     fn fadd_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
index f88923fc9f1c..a71243c7c826 100644
--- a/src/librustc_codegen_llvm/llvm/ffi.rs
+++ b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -1002,6 +1002,36 @@ extern "C" {
                          RHS: &'a Value,
                          Name: *const c_char)
                          -> &'a Value;
+    pub fn LLVMBuildNSWAdd(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
+    pub fn LLVMBuildNUWAdd(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
+    pub fn LLVMBuildNSWSub(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
+    pub fn LLVMBuildNUWSub(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
+    pub fn LLVMBuildNSWMul(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
+    pub fn LLVMBuildNUWMul(B: &Builder<'a>,
+                           LHS: &'a Value,
+                           RHS: &'a Value,
+                           Name: *const c_char)
+                           -> &'a Value;
     pub fn LLVMBuildAnd(B: &Builder<'a>,
                         LHS: &'a Value,
                         RHS: &'a Value,
diff --git a/src/librustc_codegen_ssa/traits/builder.rs b/src/librustc_codegen_ssa/traits/builder.rs
index 0c4c4547a795..a11d1ba9231c 100644
--- a/src/librustc_codegen_ssa/traits/builder.rs
+++ b/src/librustc_codegen_ssa/traits/builder.rs
@@ -88,6 +88,12 @@ pub trait BuilderMethods<'a, 'tcx: 'a>:
     fn shl(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
     fn lshr(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
     fn ashr(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_sadd(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_uadd(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_ssub(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_usub(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_smul(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
+    fn unchecked_umul(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
     fn and(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
     fn or(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;
     fn xor(&mut self, lhs: Self::Value, rhs: Self::Value) -> Self::Value;