add support for unchecked math

Author: lcnr

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 {

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,

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;