[WebAssembly] Reapply r319186: "Support bitcasted function addresses with varargs."

This puts the functionality under control of a command-line option which is
off by default to avoid breaking existing setups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320197 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 50 insertions, 11 deletions

diff --git a/test/CodeGen/WebAssembly/call.ll b/test/CodeGen/WebAssembly/call.ll
index dfa0cf5efe0..8a5e8d8c480 100644
--- a/test/CodeGen/WebAssembly/call.ll
+++ b/test/CodeGen/WebAssembly/call.ll
@@ -1,5 +1,5 @@
-; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt | FileCheck %s
-; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -fast-isel -fast-isel-abort=1 | FileCheck %s
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-temporary-workarounds=false | FileCheck %s
+; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -fast-isel -fast-isel-abort=1 -wasm-temporary-workarounds=false | FileCheck %s
 
 ; Test that basic call operations assemble as expected.
 
@@ -153,7 +153,7 @@ define void @coldcc_tail_call_void_nullary() {
 ; CHECK-LABEL: call_constexpr:
 ; CHECK-NEXT: i32.const $push[[L0:[0-9]+]]=, 2{{$}}
 ; CHECK-NEXT: i32.const $push[[L1:[0-9]+]]=, 3{{$}}
-; CHECK-NEXT: call vararg_func@FUNCTION, $pop[[L0]], $pop[[L1]]{{$}}
+; CHECK-NEXT: call .Lbitcast@FUNCTION, $pop[[L0]], $pop[[L1]]{{$}}
 ; CHECK-NEXT: call other_void_nullary@FUNCTION{{$}}
 ; CHECK-NEXT: call void_nullary@FUNCTION{{$}}
 ; CHECK-NEXT: return{{$}}
diff --git a/test/CodeGen/WebAssembly/function-bitcasts-varargs.ll b/test/CodeGen/WebAssembly/function-bitcasts-varargs.ll
new file mode 100644
index 00000000000..b5f3d2f64e9
--- /dev/null
+++ b/test/CodeGen/WebAssembly/function-bitcasts-varargs.ll
@@ -0,0 +1,31 @@
+; RUN: llc < %s -asm-verbose=false -wasm-temporary-workarounds=false | FileCheck %s
+
+; Test that function pointer casts casting away varargs are replaced with
+; wrappers.
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown-wasm"
+
+define void @callWithArgs() {
+entry:
+  call void bitcast (void (...)* @underspecified to void (i32, i32)*)(i32 0, i32 1)
+  call void(...) bitcast (void (i32, i32)* @specified to void (...)*)(i32 0, i32 1)
+  ret void
+}
+
+declare void @underspecified(...)
+declare void @specified(i32, i32)
+
+; CHECK: callWithArgs:
+; CHECK: i32.const	$push1=, 0
+; CHECK-NEXT: i32.const	$push0=, 1
+; CHECK-NEXT: call    	.Lbitcast@FUNCTION, $pop1, $pop0
+; CHECK: call    	.Lbitcast.1@FUNCTION, $pop{{[0-9]+$}}
+
+; CHECK: .Lbitcast:
+; CHECK-NEXT: .param  	i32, i32{{$}}
+; CHECK: call    	underspecified@FUNCTION, $pop{{[0-9]+$}}
+
+; CHECK: .Lbitcast.1:
+; CHECK-NEXT: .param  	i32{{$}}
+; CHECK: call    	specified@FUNCTION, $pop{{[0-9]+}}, $pop{{[0-9]+$}}
diff --git a/test/CodeGen/WebAssembly/function-bitcasts.ll b/test/CodeGen/WebAssembly/function-bitcasts.ll
index 3e796e3ff31..ab03716ef74 100644
--- a/test/CodeGen/WebAssembly/function-bitcasts.ll
+++ b/test/CodeGen/WebAssembly/function-bitcasts.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -asm-verbose=false -disable-wasm-explicit-locals -enable-emscripten-cxx-exceptions | FileCheck %s
+; RUN: llc < %s -asm-verbose=false -disable-wasm-explicit-locals -enable-emscripten-cxx-exceptions -wasm-temporary-workarounds=false | FileCheck %s
 
 ; Test that function pointer casts are replaced with wrappers.
 
@@ -20,13 +20,13 @@ declare void @foo3()
 ; CHECK-NEXT: call        .Lbitcast@FUNCTION{{$}}
 ; CHECK-NEXT: call        .Lbitcast.1@FUNCTION{{$}}
 ; CHECK-NEXT: i32.const   $push[[L0:[0-9]+]]=, 0
-; CHECK-NEXT: call        .Lbitcast.2@FUNCTION, $pop[[L0]]{{$}}
+; CHECK-NEXT: call        .Lbitcast.4@FUNCTION, $pop[[L0]]{{$}}
 ; CHECK-NEXT: i32.const   $push[[L1:[0-9]+]]=, 0
-; CHECK-NEXT: call        .Lbitcast.2@FUNCTION, $pop[[L1]]{{$}}
+; CHECK-NEXT: call        .Lbitcast.4@FUNCTION, $pop[[L1]]{{$}}
 ; CHECK-NEXT: i32.const   $push[[L2:[0-9]+]]=, 0
-; CHECK-NEXT: call        .Lbitcast.2@FUNCTION, $pop[[L2]]{{$}}
+; CHECK-NEXT: call        .Lbitcast.4@FUNCTION, $pop[[L2]]{{$}}
 ; CHECK-NEXT: call        foo0@FUNCTION
-; CHECK-NEXT: i32.call    $drop=, .Lbitcast.3@FUNCTION{{$}}
+; CHECK-NEXT: i32.call    $drop=, .Lbitcast.5@FUNCTION{{$}}
 ; CHECK-NEXT: call        foo2@FUNCTION{{$}}
 ; CHECK-NEXT: call        foo1@FUNCTION{{$}}
 ; CHECK-NEXT: call        foo3@FUNCTION{{$}}
@@ -54,10 +54,10 @@ entry:
 ; CHECK-LABEL: test_varargs:
 ; CHECK:      set_global
 ; CHECK:      i32.const   $push[[L3:[0-9]+]]=, 0{{$}}
-; CHECK-NEXT: call        vararg@FUNCTION, $pop[[L3]]{{$}}
+; CHECK-NEXT: call        .Lbitcast.2@FUNCTION, $pop[[L3]]{{$}}
 ; CHECK-NEXT: i32.const   $push[[L4:[0-9]+]]=, 0{{$}}
 ; CHECK-NEXT: i32.store   0($[[L5:[0-9]+]]), $pop[[L4]]{{$}}
-; CHECK-NEXT: call        plain@FUNCTION, $[[L5]]{{$}}
+; CHECK-NEXT: call        .Lbitcast.3@FUNCTION, $[[L5]]{{$}}
 define void @test_varargs() {
   call void bitcast (void (...)* @vararg to void (i32)*)(i32 0)
   call void (...) bitcast (void (i32)* @plain to void (...)*)(i32 0)
@@ -147,11 +147,19 @@ end:
 ; CHECK-NEXT: end_function
 
 ; CHECK-LABEL: .Lbitcast.2:
+; CHECK: call        vararg@FUNCTION, $1{{$}}
+; CHECK: end_function
+
+; CHECK-LABEL: .Lbitcast.3:
+; CHECK: call        plain@FUNCTION, $1{{$}}
+; CHECK: end_function
+
+; CHECK-LABEL: .Lbitcast.4:
 ; CHECK-NEXT: .param      i32
 ; CHECK-NEXT: call        foo0@FUNCTION{{$}}
 ; CHECK-NEXT: end_function
 
-; CHECK-LABEL: .Lbitcast.3:
+; CHECK-LABEL: .Lbitcast.5:
 ; CHECK-NEXT: .result     i32
 ; CHECK-NEXT: call        foo1@FUNCTION{{$}}
 ; CHECK-NEXT: copy_local  $push0=, $0