machinst x64: lower Ctz using the Bsf x86 instruction

2020-07-06 15:44:12 +02:00
parent 33e0d05645
commit 6f5403a94b
3 changed files with 36 additions and 0 deletions
--- a/cranelift/codegen/src/isa/x64/inst/emit.rs
+++ b/cranelift/codegen/src/isa/x64/inst/emit.rs
@@ -566,6 +566,7 @@ pub(crate) fn emit(

            let (opcode, num_opcodes) = match op {
                ReadOnlyGprRmROpcode::Bsr => (0x0fbd, 2),
+                ReadOnlyGprRmROpcode::Bsf => (0x0fbc, 2),
            };

            match src {