[llvm] r269683 - [WebAssembly] Mark COPY_LOCAL and TEE_LOCAL instructions has having no side effects.

[Dan Gohman via llvm-commits]

Author: djg
Date: Mon May 16 14:16:32 2016
New Revision: 269683

URL: http://llvm.org/viewvc/llvm-project?rev=269683&view=rev
Log:
[WebAssembly] Mark COPY_LOCAL and TEE_LOCAL instructions has having no side effects.

Modified:
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
    llvm/trunk/test/CodeGen/WebAssembly/userstack.ll

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td?rev=269683&r1=269682&r2=269683&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td Mon May 16 14:16:32 2016
@@ -110,6 +110,7 @@ let Defs = [ARGUMENTS] in {
 // get_local and set_local are not generated by instruction selection; they
 // are implied by virtual register uses and defs.
 multiclass LOCAL<WebAssemblyRegClass vt> {
+let hasSideEffects = 0 in {
   // COPY_LOCAL is not an actual instruction in wasm, but since we allow
   // get_local and set_local to be implicit, we can have a COPY_LOCAL which
   // is actually a no-op because all the work is done in the implied
@@ -124,6 +125,7 @@ multiclass LOCAL<WebAssemblyRegClass vt>
   let isAsCheapAsAMove = 1 in
   def TEE_LOCAL_#vt : I<(outs vt:$res, vt:$also), (ins vt:$src), [],
                         "tee_local\t$res, $also, $src">;
+} // hasSideEffects = 0
 }
 defm : LOCAL<I32>;
 defm : LOCAL<I64>;

Modified: llvm/trunk/test/CodeGen/WebAssembly/userstack.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/userstack.ll?rev=269683&r1=269682&r2=269683&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/userstack.ll (original)
+++ llvm/trunk/test/CodeGen/WebAssembly/userstack.ll Mon May 16 14:16:32 2016
@@ -131,10 +131,10 @@ define void @allocarray_inbounds() {
 
 ; CHECK-LABEL: dynamic_alloca:
 define void @dynamic_alloca(i32 %alloc) {
+ ; CHECK: i32.const $push[[L7:.+]]=, __stack_pointer
  ; CHECK: i32.const $push[[L1:.+]]=, __stack_pointer
  ; CHECK-NEXT: i32.load $push[[L13:.+]]=, 0($pop[[L1]])
  ; CHECK-NEXT: tee_local $push[[L12:.+]]=, [[SP:.+]], $pop[[L13]]{{$}}
- ; CHECK-NEXT: copy_local [[FP:.+]]=, $pop[[L12]]{{$}}
  ; Target independent codegen bumps the stack pointer.
  ; CHECK: i32.sub
  ; Check that SP is written back to memory after decrement
@@ -144,7 +144,7 @@ define void @dynamic_alloca(i32 %alloc)
  ; CHECK: call ext_func_i32 at FUNCTION
  call void @ext_func_i32(i32* %r)
  ; CHECK: i32.const $push[[L3:.+]]=, __stack_pointer
- ; CHECK-NEXT: i32.store $discard=, 0($pop[[L3]]), [[FP]]
+ ; CHECK: i32.store $discard=, 0($pop[[L3]]), $pop{{.+}}
  ret void
 }
 
@@ -169,12 +169,14 @@ define void @dynamic_alloca_redzone(i32
 ; CHECK-LABEL: dynamic_static_alloca:
 define void @dynamic_static_alloca(i32 %alloc) noredzone {
  ; Decrement SP in the prolog by the static amount and writeback to memory.
+ ; CHECK: i32.const $push[[L7:.+]]=, __stack_pointer
+ ; CHECK: i32.const $push[[L8:.+]]=, __stack_pointer
  ; CHECK: i32.const $push[[L9:.+]]=, __stack_pointer
  ; CHECK-NEXT: i32.load $push[[L10:.+]]=, 0($pop[[L9]])
  ; CHECK-NEXT: i32.const $push[[L11:.+]]=, 16
  ; CHECK-NEXT: i32.sub $push[[L20:.+]]=, $pop[[L10]], $pop[[L11]]
  ; CHECK-NEXT: tee_local $push[[L19:.+]]=, $[[FP:.+]]=, $pop[[L20]]
- ; CHECK:      i32.store $push[[L0:.+]]=, 0($pop{{.+}}), $[[FP]]
+ ; CHECK:      i32.store $push[[L0:.+]]=, 0($pop{{.+}}), $pop{{.+}}
  ; Decrement SP in the body by the dynamic amount.
  ; CHECK: i32.sub
  ; Writeback to memory.