Use memset when repeating 128bit zero value

diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index 26b9fbf44284628cdf19e8bbd042de40375d8670..574746e340b7bff7f041ccfb4d9f9dca62e4d7fe 100644 (file)
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -87,7 +87,7 @@ pub fn codegen_rvalue(
                     let size = bx.const_usize(dest.layout.size.bytes());
 
                     // Use llvm.memset.p0i8.* to initialize all zero arrays
-                    if bx.cx().const_to_opt_uint(v) == Some(0) {
+                    if bx.cx().const_to_opt_u128(v, false) == Some(0) {
                         let fill = bx.cx().const_u8(0);
                         bx.memset(start, fill, size, dest.align, MemFlags::empty());
                         return bx;