Add x86 recipe for vconst

cranelift/codegen/meta/src/isa/x86/recipes.rs

@@ -399,6 +399,7 @@ pub fn define<'shared>(
     let f_unary_ieee32 = formats.by_name("UnaryIeee32");
     let f_unary_ieee64 = formats.by_name("UnaryIeee64");
     let f_unary_imm = formats.by_name("UnaryImm");
+    let f_unary_imm128 = formats.by_name("UnaryImm128");
 
     // Predicates shorthands.
     let use_sse41 = settings.predicate_by_name("use_sse41");
@@ -2382,6 +2383,19 @@ pub fn define<'shared>(
             ),
     );
 
+    recipes.add_template_recipe(
+        EncodingRecipeBuilder::new("vconst", f_unary_imm128, 5)
+            .operands_out(vec![fpr])
+            .clobbers_flags(false)
+            .emit(
+                r#"
+                    {{PUT_OP}}(bits, rex2(0, out_reg0), sink);
+                    modrm_riprel(out_reg0, sink);
+                    const_disp4(imm, func, sink);
+                "#,
+            ),
+    );
+
     recipes.add_template_recipe(
         EncodingRecipeBuilder::new("jt_base", f_branch_table_base, 5)
             .operands_out(vec![gpr])

cranelift/codegen/src/isa/x86/binemit.rs

@@ -4,7 +4,7 @@ use super::enc_tables::{needs_offset, needs_sib_byte};
 use super::registers::RU;
 use crate::binemit::{bad_encoding, CodeSink, Reloc};
 use crate::ir::condcodes::{CondCode, FloatCC, IntCC};
-use crate::ir::{Ebb, Function, Inst, InstructionData, JumpTable, Opcode, TrapCode};
+use crate::ir::{Constant, Ebb, Function, Inst, InstructionData, JumpTable, Opcode, TrapCode};
 use crate::isa::{RegUnit, StackBase, StackBaseMask, StackRef, TargetIsa};
 use crate::regalloc::RegDiversions;
 
@@ -341,3 +341,11 @@ fn jt_disp4<CS: CodeSink + ?Sized>(jt: JumpTable, func: &Function, sink: &mut CS
     sink.put4(delta);
     sink.reloc_jt(Reloc::X86PCRelRodata4, jt);
 }
+
+/// Emit a four-byte displacement to `constant`
+fn const_disp4<CS: CodeSink + ?Sized>(constant: Constant, func: &Function, sink: &mut CS) {
+    let offset = func.dfg.constants.get_offset(constant);
+    let delta = offset.wrapping_sub(sink.offset() + 4);
+    sink.put4(delta);
+    sink.reloc_constant(Reloc::X86PCRelRodata4, offset);
+}