Emit fixed use constraints for indirect call destinations

Work around bytecodealliance/regalloc2#145 in the same way that we do for tail calls -- using a fixed use constraint.
elliottt · Mar 11, 2024 · 1ed4a14 · 1ed4a14
1 parent 99ea051
commit 1ed4a14
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Showing 2 changed files with 19 additions and 6 deletions.
diff --git a/cranelift/codegen/src/isa/aarch64/inst/mod.rs b/cranelift/codegen/src/isa/aarch64/inst/mod.rs
@@ -867,12 +867,20 @@ fn aarch64_get_operands<F: Fn(VReg) -> VReg>(inst: &Inst, collector: &mut Operan
             collector.reg_clobbers(info.clobbers);
         }
         &Inst::CallInd { ref info, .. } => {
-            if info.callee_callconv == CallConv::Tail {
-                // TODO(https://github.com/bytecodealliance/regalloc2/issues/145):
-                // This shouldn't be a fixed register constraint.
-                collector.reg_fixed_use(info.rn, xreg(1));
-            } else {
-                collector.reg_use(info.rn);
+            match info.callee_callconv {
+                CallConv::Tail => {
+                    // TODO(https://github.com/bytecodealliance/regalloc2/issues/145):
+                    // This shouldn't be a fixed register constraint.
+                    collector.reg_fixed_use(info.rn, xreg(1));
+                }
+                CallConv::Winch => {
+                    // TODO(https://github.com/bytecodealliance/regalloc2/issues/145):
+                    // This shouldn't be a fixed register constraint.
+                    collector.reg_fixed_use(info.rn, xreg(1));
+                }
+                _ => {
+                    collector.reg_use(info.rn);
+                }
             }
             for u in &info.uses {
                 collector.reg_fixed_use(u.vreg, u.preg);

diff --git a/cranelift/codegen/src/isa/x64/inst/mod.rs b/cranelift/codegen/src/isa/x64/inst/mod.rs
@@ -2370,6 +2370,11 @@ fn x64_get_operands<F: Fn(VReg) -> VReg>(inst: &Inst, collector: &mut OperandCol
                     // This shouldn't be a fixed register constraint.
                     collector.reg_fixed_use(*reg, regs::r15())
                 }
+                RegMem::Reg { reg } if info.callee_conv == CallConv::Winch => {
+                    // TODO(https://github.com/bytecodealliance/regalloc2/issues/145):
+                    // This shouldn't be a fixed register constraint.
+                    collector.reg_fixed_use(*reg, regs::r15())
+                }
                 _ => dest.get_operands(collector),
             }
             for u in &info.uses {