[WebAssembly] Fold nuw global add to load offset

badumbatish · badumbatish · commit 3dfe71a7fd83 · 2025-07-01T10:46:01.000-07:00
Fold nuw global add to a load.

Fix extra tests that involves loads in exception-legacy, eh-lsda, and address-offsets.
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp
@@ -354,6 +354,16 @@ bool WebAssemblyDAGToDAGISel::SelectAddrAddOperands(MVT OffsetType, SDValue N,
       Addr = OtherOp;
       return true;
     }
+
+    // Fold Add of Global Address straight into load
+    if (Op.getOpcode() == WebAssemblyISD::Wrapper)
+      Op = Op.getOperand(0);
+
+    if (Op.getOpcode() == ISD::TargetGlobalAddress) {
+      Addr = OtherOp;
+      Offset = Op;
+      return true;
+    }
   }
   return false;
 }
diff --git a/llvm/test/CodeGen/WebAssembly/address-offsets.ll b/llvm/test/CodeGen/WebAssembly/address-offsets.ll
@@ -12,8 +12,8 @@ define i32 @load_test0() {
 ; CHECK-LABEL: load_test0:
 ; CHECK:         .functype load_test0 () -> (i32)
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    global.get $push0=, g@GOT
-; CHECK-NEXT:    i32.load $push1=, 40($pop0)
+; CHECK-NEXT:    i32.const $push0=, 40
+; CHECK-NEXT:    i32.load $push1=, g@GOT($pop0)
 ; CHECK-NEXT:    return $pop1
   %t = load i32, ptr getelementptr inbounds ([0 x i32], ptr @g, i32 0, i32 10), align 4
   ret i32 %t
@@ -395,8 +395,8 @@ define void @store_test0(i32 %i) {
 ; CHECK-LABEL: store_test0:
 ; CHECK:         .functype store_test0 (i32) -> ()
 ; CHECK-NEXT:  # %bb.0:
-; CHECK-NEXT:    global.get $push0=, g@GOT
-; CHECK-NEXT:    i32.store 40($pop0), $0
+; CHECK-NEXT:    i32.const $push0=, 40
+; CHECK-NEXT:    i32.store g@GOT($pop0), $0
 ; CHECK-NEXT:    return
   store i32 %i, ptr getelementptr inbounds ([0 x i32], ptr @g, i32 0, i32 10), align 4
   ret void
diff --git a/llvm/test/CodeGen/WebAssembly/eh-lsda.ll b/llvm/test/CodeGen/WebAssembly/eh-lsda.ll
@@ -1,9 +1,9 @@
-; RUN: llc < %s --mtriple=wasm32-unknown-unknown -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=32
-; RUN: llc < %s --mtriple=wasm64-unknown-unknown -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=64
-; RUN: llc < %s --mtriple=wasm32-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=32
-; RUN: llc < %s --mtriple=wasm64-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=64
-; RUN: llc < %s --mtriple=wasm32-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -relocation-model=pic | FileCheck %s -check-prefixes=CHECK,PIC -DPTR=32
-; RUN: llc < %s --mtriple=wasm64-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -relocation-model=pic | FileCheck %s -check-prefixes=CHECK,PIC -DPTR=64
+; RUN: llc < %s --mtriple=wasm32-unknown-unknown -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=32 -DALIGNMENT=4
+; RUN: llc < %s --mtriple=wasm64-unknown-unknown -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=64 -DALIGNMENT=8
+; RUN: llc < %s --mtriple=wasm32-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=32 -DALIGNMENT=4
+; RUN: llc < %s --mtriple=wasm64-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s -check-prefixes=CHECK,NOPIC -DPTR=64 -DALIGNMENT=8
+; RUN: llc < %s --mtriple=wasm32-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -relocation-model=pic | FileCheck %s -check-prefixes=CHECK,PIC -DPTR=32 -DALIGNMENT=4
+; RUN: llc < %s --mtriple=wasm64-unknown-emscripten -wasm-disable-explicit-locals -wasm-keep-registers -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -relocation-model=pic | FileCheck %s -check-prefixes=CHECK,PIC -DPTR=64  -DALIGNMENT=8
 
 @_ZTIi = external constant ptr
 @_ZTIf = external constant ptr
@@ -66,18 +66,17 @@ try.cont:                                         ; preds = %entry, %catch.start
 
 ; CHECK-LABEL: test1:
 ; In static linking, we load GCC_except_table as a constant directly.
-; NOPIC:      i[[PTR]].const  $push[[CONTEXT:.*]]=, __wasm_lpad_context
+; NOPIC:      i[[PTR]].const  $push[[CONTEXT:.*]]=, [[ALIGNMENT]]
 ; NOPIC-NEXT: i[[PTR]].const  $push[[EXCEPT_TABLE:.*]]=, GCC_except_table1
-; NOPIC-NEXT: i[[PTR]].store  {{[48]}}($pop[[CONTEXT]]), $pop[[EXCEPT_TABLE]]
+; NOPIC-NEXT: i[[PTR]].store  __wasm_lpad_context($pop[[CONTEXT]]), $pop[[EXCEPT_TABLE]]
 
 ; In case of PIC, we make GCC_except_table symbols a relative on based on
 ; __memory_base.
 ; PIC:        global.get  $push[[CONTEXT:.*]]=, __wasm_lpad_context@GOT
-; PIC-NEXT:   local.tee  $push{{.*}}=, $[[CONTEXT_LOCAL:.*]]=, $pop[[CONTEXT]]
 ; PIC:        global.get  $push[[MEMORY_BASE:.*]]=, __memory_base
 ; PIC-NEXT:   i[[PTR]].const  $push[[EXCEPT_TABLE_REL:.*]]=, GCC_except_table1@MBREL
 ; PIC-NEXT:   i[[PTR]].add   $push[[EXCEPT_TABLE:.*]]=, $pop[[MEMORY_BASE]], $pop[[EXCEPT_TABLE_REL]]
-; PIC-NEXT:   i[[PTR]].store  {{[48]}}($[[CONTEXT_LOCAL]]), $pop[[EXCEPT_TABLE]]
+; PIC-NEXT:   i[[PTR]].store  __wasm_lpad_context@GOT(${{.*}}), $pop[[EXCEPT_TABLE]]
 
 ; CHECK: .section  .rodata.gcc_except_table,"",@
 ; CHECK-NEXT:   .p2align  2
diff --git a/llvm/test/CodeGen/WebAssembly/exception-legacy.ll b/llvm/test/CodeGen/WebAssembly/exception-legacy.ll
@@ -34,7 +34,7 @@ define void @throw(ptr %p) {
 ; CHECK:       call      foo
 ; CHECK:     catch     $[[EXN:[0-9]+]]=, __cpp_exception
 ; CHECK:       global.set  __stack_pointer
-; CHECK:       i32.{{store|const}} {{.*}} __wasm_lpad_context
+; CHECK:       i32.{{store|const}} {{.*}} 4
 ; CHECK:       call       $drop=, _Unwind_CallPersonality, $[[EXN]]
 ; CHECK:       block
 ; CHECK:         br_if     0
diff --git a/llvm/test/CodeGen/WebAssembly/offset.ll b/llvm/test/CodeGen/WebAssembly/offset.ll
@@ -65,10 +65,8 @@ define i32 @load_i32_with_folded_gep_offset_nuw(ptr %p) {
 define hidden signext i8 @global_load_i32_with_folded_gep_offset_nonconst_nuw(i32 noundef %idx) local_unnamed_addr {
 ; CHECK-LABEL: global_load_i32_with_folded_gep_offset_nonconst_nuw:
 ; CHECK:         .functype global_load_i32_with_folded_gep_offset_nonconst_nuw (i32) -> (i32)
-; CHECK:    i32.const $push0=, global_data
-; CHECK:    i32.add $push1=, $0, $pop0
-; CHECK:    i32.load8_s $push2=, 0($pop1)
-; CHECK:    return $pop2
+; CHECK:    i32.load8_s $push0=, global_data($0)
+; CHECK:    return $pop0
 entry:
   %arrayidx = getelementptr inbounds nuw [12 x i8], ptr @global_data, i32 0, i32 %idx
   %0 = load i8, ptr %arrayidx, align 1

Original file line number	Diff line number	Diff line change
`@@ -354,6 +354,16 @@ bool WebAssemblyDAGToDAGISel::SelectAddrAddOperands(MVT OffsetType, SDValue N,`
`354`	`354`	`Addr = OtherOp;`
`355`	`355`	`return true;`
`356`	`356`	`}`
	`357`	`+`
	`358`	`+ // Fold Add of Global Address straight into load`
	`359`	`+ if (Op.getOpcode() == WebAssemblyISD::Wrapper)`
	`360`	`+ Op = Op.getOperand(0);`
	`361`	`+`
	`362`	`+ if (Op.getOpcode() == ISD::TargetGlobalAddress) {`
	`363`	`+ Addr = OtherOp;`
	`364`	`+ Offset = Op;`
	`365`	`+ return true;`
	`366`	`+ }`
`357`	`367`	`}`
`358`	`368`	`return false;`
`359`	`369`	`}`