Index: lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp =================================================================== --- lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp +++ lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp @@ -54,7 +54,7 @@ void OptimizeReturned::visitCallSite(CallSite CS) { for (unsigned i = 0, e = CS.getNumArgOperands(); i < e; ++i) - if (CS.paramHasAttr(0, Attribute::Returned)) { + if (CS.paramHasAttr(i, Attribute::Returned)) { Instruction *Inst = CS.getInstruction(); Value *Arg = CS.getArgOperand(i); // Ignore constants, globals, undef, etc. Index: test/CodeGen/WebAssembly/returned.ll =================================================================== --- test/CodeGen/WebAssembly/returned.ll +++ test/CodeGen/WebAssembly/returned.ll @@ -47,3 +47,34 @@ ret void } declare i32* @returns_arg(i32* returned) + +; Test that the optimization isn't performed on arguments without the +; "returned" attribute. + +; CHECK-LABEL: test_other_skipped: +; CHECK-NEXT: .param i32, i32, f64{{$}} +; CHECK-NEXT: {{^}} i32.call $drop=, do_something@FUNCTION, $0, $1, $2{{$}} +; CHECK-NEXT: {{^}} call do_something_with_i32@FUNCTION, $1{{$}} +; CHECK-NEXT: {{^}} call do_something_with_double@FUNCTION, $2{{$}} +declare i32 @do_something(i32 returned, i32, double) +declare void @do_something_with_i32(i32) +declare void @do_something_with_double(double) +define void @test_other_skipped(i32 %a, i32 %b, double %c) { + %call = call i32 @do_something(i32 %a, i32 %b, double %c) + call void @do_something_with_i32(i32 %b) + call void @do_something_with_double(double %c) + ret void +} + +; Test that the optimization is performed on arguments other than the first. + +; CHECK-LABEL: test_second_arg: +; CHECK-NEXT: .param i32, i32{{$}} +; CHECK-NEXT: .result i32{{$}} +; CHECK-NEXT: {{^}} i32.call $push0=, do_something_else@FUNCTION, $0, $1{{$}} +; CHECK-NEXT: return $pop0{{$}} +declare i32 @do_something_else(i32, i32 returned) +define i32 @test_second_arg(i32 %a, i32 %b) { + %call = call i32 @do_something_else(i32 %a, i32 %b) + ret i32 %b +}