[lld] [llvm] [WebAssembly] Use 64-bit table when targeting wasm64 (PR #92042)
Sam Clegg via llvm-commits
llvm-commits at lists.llvm.org
Thu May 23 18:19:13 PDT 2024
https://github.com/sbc100 updated https://github.com/llvm/llvm-project/pull/92042
>From 2ff10d99fa298e2638ccccedf01ed743ea652344 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc at chromium.org>
Date: Mon, 13 May 2024 14:42:34 -0700
Subject: [PATCH] [WebAssembly] Use 64-bit table when targeting wasm64
See https://github.com/WebAssembly/memory64/issues/51
---
lld/test/wasm/shared64.s | 14 +++++---------
lld/wasm/Driver.cpp | 10 ----------
lld/wasm/Symbols.cpp | 2 --
lld/wasm/Symbols.h | 5 -----
lld/wasm/SyntheticSections.cpp | 8 +++-----
lld/wasm/Writer.cpp | 10 ++++------
.../lib/Target/WebAssembly/WebAssemblyFastISel.cpp | 12 ------------
.../Target/WebAssembly/WebAssemblyISelLowering.cpp | 14 --------------
.../WebAssembly/fast-isel-call-indirect64.ll | 14 --------------
.../test/CodeGen/WebAssembly/function-pointer64.ll | 5 ++---
10 files changed, 14 insertions(+), 80 deletions(-)
delete mode 100644 llvm/test/CodeGen/WebAssembly/fast-isel-call-indirect64.ll
diff --git a/lld/test/wasm/shared64.s b/lld/test/wasm/shared64.s
index 3401faed8610c..73f77436cabf9 100644
--- a/lld/test/wasm/shared64.s
+++ b/lld/test/wasm/shared64.s
@@ -154,6 +154,7 @@ get_local_func_address:
# CHECK-NEXT: Index: 0
# CHECK-NEXT: ElemType: FUNCREF
# CHECK-NEXT: Limits:
+# CHECK-NEXT: Flags: [ IS_64 ]
# CHECK-NEXT: Minimum: 0x2
# CHECK-NEXT: - Module: env
# CHECK-NEXT: Field: __stack_pointer
@@ -170,11 +171,6 @@ get_local_func_address:
# CHECK-NEXT: Kind: GLOBAL
# CHECK-NEXT: GlobalType: I64
# CHECK-NEXT: GlobalMutable: false
-# CHECK-NEXT: - Module: env
-# CHECK-NEXT: Field: __table_base32
-# CHECK-NEXT: Kind: GLOBAL
-# CHECK-NEXT: GlobalType: I32
-# CHECK-NEXT: GlobalMutable: false
# CHECK-NEXT: - Module: GOT.mem
# CHECK-NEXT: Field: indirect_func
# CHECK-NEXT: Kind: GLOBAL
@@ -209,7 +205,7 @@ get_local_func_address:
# CHECK-NEXT: Segments:
# CHECK-NEXT: - Offset:
# CHECK-NEXT: Opcode: GLOBAL_GET
-# CHECK-NEXT: Index: 3
+# CHECK-NEXT: Index: 2
# CHECK-NEXT: Functions: [ 3, 2 ]
# check the generated code in __wasm_call_ctors and __wasm_apply_data_relocs functions
@@ -223,7 +219,7 @@ get_local_func_address:
# DIS-NEXT: i64.const 4
# DIS-NEXT: global.get 1
# DIS-NEXT: i64.add
-# DIS-NEXT: global.get 5
+# DIS-NEXT: global.get 4
# DIS-NEXT: i64.store 0:p2align=2
# DIS-NEXT: i64.const 12
# DIS-NEXT: global.get 1
@@ -242,12 +238,12 @@ get_local_func_address:
# DIS-NEXT: i64.const 24
# DIS-NEXT: global.get 1
# DIS-NEXT: i64.add
-# DIS-NEXT: global.get 6
+# DIS-NEXT: global.get 5
# DIS-NEXT: i64.store 0:p2align=2
# DIS-NEXT: i64.const 32
# DIS-NEXT: global.get 1
# DIS-NEXT: i64.add
-# DIS-NEXT: global.get 7
+# DIS-NEXT: global.get 6
# DIS-NEXT: i32.const 4
# DIS-NEXT: i32.add
# DIS-NEXT: i32.store 0
diff --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp
index d5d763b0a4ae1..cc79f80d005dc 100644
--- a/lld/wasm/Driver.cpp
+++ b/lld/wasm/Driver.cpp
@@ -870,13 +870,6 @@ static void createSyntheticSymbols() {
WasmSym::tableBase = createUndefinedGlobal("__table_base", globalType);
WasmSym::memoryBase->markLive();
WasmSym::tableBase->markLive();
- if (is64) {
- WasmSym::tableBase32 =
- createUndefinedGlobal("__table_base32", &globalTypeI32);
- WasmSym::tableBase32->markLive();
- } else {
- WasmSym::tableBase32 = nullptr;
- }
} else {
// For non-PIC code
WasmSym::stackPointer = createGlobalVariable("__stack_pointer", true);
@@ -923,9 +916,6 @@ static void createOptionalSymbols() {
WasmSym::heapEnd = symtab->addOptionalDataSymbol("__heap_end");
WasmSym::definedMemoryBase = symtab->addOptionalDataSymbol("__memory_base");
WasmSym::definedTableBase = symtab->addOptionalDataSymbol("__table_base");
- if (config->is64.value_or(false))
- WasmSym::definedTableBase32 =
- symtab->addOptionalDataSymbol("__table_base32");
}
// For non-shared memory programs we still need to define __tls_base since we
diff --git a/lld/wasm/Symbols.cpp b/lld/wasm/Symbols.cpp
index ace6bade02d43..687728d00c856 100644
--- a/lld/wasm/Symbols.cpp
+++ b/lld/wasm/Symbols.cpp
@@ -96,8 +96,6 @@ GlobalSymbol *WasmSym::tlsSize;
GlobalSymbol *WasmSym::tlsAlign;
UndefinedGlobal *WasmSym::tableBase;
DefinedData *WasmSym::definedTableBase;
-UndefinedGlobal *WasmSym::tableBase32;
-DefinedData *WasmSym::definedTableBase32;
UndefinedGlobal *WasmSym::memoryBase;
DefinedData *WasmSym::definedMemoryBase;
TableSymbol *WasmSym::indirectFunctionTable;
diff --git a/lld/wasm/Symbols.h b/lld/wasm/Symbols.h
index 38586bbd13236..65a062b8321b9 100644
--- a/lld/wasm/Symbols.h
+++ b/lld/wasm/Symbols.h
@@ -603,11 +603,6 @@ struct WasmSym {
// Used in PIC code for offset of indirect function table
static UndefinedGlobal *tableBase;
static DefinedData *definedTableBase;
- // 32-bit copy in wasm64 to work around init expr limitations.
- // These can potentially be removed again once we have
- // https://github.com/WebAssembly/extended-const
- static UndefinedGlobal *tableBase32;
- static DefinedData *definedTableBase32;
// __memory_base
// Used in PIC code for offset of global data
diff --git a/lld/wasm/SyntheticSections.cpp b/lld/wasm/SyntheticSections.cpp
index 72e255951608e..b359e0fdc856c 100644
--- a/lld/wasm/SyntheticSections.cpp
+++ b/lld/wasm/SyntheticSections.cpp
@@ -584,12 +584,10 @@ void ElemSection::writeBody() {
initExpr.Extended = false;
if (ctx.isPic) {
initExpr.Inst.Opcode = WASM_OPCODE_GLOBAL_GET;
- initExpr.Inst.Value.Global =
- (config->is64.value_or(false) ? WasmSym::tableBase32
- : WasmSym::tableBase)
- ->getGlobalIndex();
+ initExpr.Inst.Value.Global = WasmSym::tableBase->getGlobalIndex();
} else {
- initExpr.Inst.Opcode = WASM_OPCODE_I32_CONST;
+ bool is64 = config->is64.value_or(false);
+ initExpr.Inst.Opcode = is64 ? WASM_OPCODE_I64_CONST : WASM_OPCODE_I32_CONST;
initExpr.Inst.Value.Int32 = config->tableBase;
}
writeInitExpr(os, initExpr);
diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index 55eff995fb8a1..7a015764b77ca 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -939,6 +939,8 @@ static void finalizeIndirectFunctionTable() {
limits.Flags |= WASM_LIMITS_FLAG_HAS_MAX;
limits.Maximum = limits.Minimum;
}
+ if (config->is64.value_or(false))
+ limits.Flags |= WASM_LIMITS_FLAG_IS_64;
WasmSym::indirectFunctionTable->setLimits(limits);
}
@@ -1691,12 +1693,8 @@ void Writer::createSyntheticSectionsPostLayout() {
void Writer::run() {
// For PIC code the table base is assigned dynamically by the loader.
// For non-PIC, we start at 1 so that accessing table index 0 always traps.
- if (!ctx.isPic) {
- if (WasmSym::definedTableBase)
- WasmSym::definedTableBase->setVA(config->tableBase);
- if (WasmSym::definedTableBase32)
- WasmSym::definedTableBase32->setVA(config->tableBase);
- }
+ if (!ctx.isPic && WasmSym::definedTableBase)
+ WasmSym::definedTableBase->setVA(config->tableBase);
log("-- createOutputSegments");
createOutputSegments();
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
index 1c62290704fe4..26e13948bc9a6 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
@@ -885,18 +885,6 @@ bool WebAssemblyFastISel::selectCall(const Instruction *I) {
Table->setNoStrip();
MIB.addImm(0);
}
- // See if we must truncate the function pointer.
- // CALL_INDIRECT takes an i32, but in wasm64 we represent function pointers
- // as 64-bit for uniformity with other pointer types.
- // See also: WebAssemblyISelLowering.cpp: LowerCallResults
- if (Subtarget->hasAddr64()) {
- auto Wrap = BuildMI(*FuncInfo.MBB, std::prev(FuncInfo.InsertPt), MIMD,
- TII.get(WebAssembly::I32_WRAP_I64));
- Register Reg32 = createResultReg(&WebAssembly::I32RegClass);
- Wrap.addReg(Reg32, RegState::Define);
- Wrap.addReg(CalleeReg);
- CalleeReg = Reg32;
- }
}
for (unsigned ArgReg : Args)
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 527bb4c9fbea6..d524539944170 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -576,20 +576,6 @@ LowerCallResults(MachineInstr &CallResults, DebugLoc DL, MachineBasicBlock *BB,
const MCInstrDesc &MCID = TII.get(CallOp);
MachineInstrBuilder MIB(MF, MF.CreateMachineInstr(MCID, DL));
- // See if we must truncate the function pointer.
- // CALL_INDIRECT takes an i32, but in wasm64 we represent function pointers
- // as 64-bit for uniformity with other pointer types.
- // See also: WebAssemblyFastISel::selectCall
- if (IsIndirect && MF.getSubtarget<WebAssemblySubtarget>().hasAddr64()) {
- Register Reg32 =
- MF.getRegInfo().createVirtualRegister(&WebAssembly::I32RegClass);
- auto &FnPtr = CallParams.getOperand(0);
- BuildMI(*BB, CallResults.getIterator(), DL,
- TII.get(WebAssembly::I32_WRAP_I64), Reg32)
- .addReg(FnPtr.getReg());
- FnPtr.setReg(Reg32);
- }
-
// Move the function pointer to the end of the arguments for indirect calls
if (IsIndirect) {
auto FnPtr = CallParams.getOperand(0);
diff --git a/llvm/test/CodeGen/WebAssembly/fast-isel-call-indirect64.ll b/llvm/test/CodeGen/WebAssembly/fast-isel-call-indirect64.ll
deleted file mode 100644
index 8224c3bc4e374..0000000000000
--- a/llvm/test/CodeGen/WebAssembly/fast-isel-call-indirect64.ll
+++ /dev/null
@@ -1,14 +0,0 @@
-; RUN: llc < %s -fast-isel --mtriple=wasm64 -asm-verbose=false -wasm-keep-registers | FileCheck %s
-
-target triple = "wasm64"
-
-; Ensure fast isel also lowers function pointers to 32-bit.
-
-; CHECK: local.get $push[[L0:[0-9]+]]=, 0
-; CHECK-NEXT: i32.wrap_i64 $push[[L1:[0-9]+]]=, $pop[[L0]]
-; CHECK-NEXT: call_indirect $pop[[L1]]
-
-define hidden void @f(ptr %g) {
- call void %g()
- ret void
-}
diff --git a/llvm/test/CodeGen/WebAssembly/function-pointer64.ll b/llvm/test/CodeGen/WebAssembly/function-pointer64.ll
index c7c90f6b7ac21..7f98d3e648bd4 100644
--- a/llvm/test/CodeGen/WebAssembly/function-pointer64.ll
+++ b/llvm/test/CodeGen/WebAssembly/function-pointer64.ll
@@ -34,7 +34,6 @@ entry:
; CHECK: .functype foo (i64) -> ()
; CHECK-NEXT: i32.const 1
; CHECK-NEXT: local.get 0
-; CHECK-NEXT: i32.wrap_i64
; CHECK-NEXT: call_indirect (i32) -> ()
; REF: call_indirect __indirect_function_table, (i32) -> ()
@@ -53,10 +52,10 @@ entry:
; YAML: - Type: CODE
; YAML: - Type: R_WASM_TABLE_INDEX_SLEB64
; YAML-NEXT: Index: 0
-; YAML-NEXT: Offset: 0x16
+; YAML-NEXT: Offset: 0x15
; YAML: - Type: R_WASM_TABLE_INDEX_SLEB64
; YAML-NEXT: Index: 0
-; YAML-NEXT: Offset: 0x29
+; YAML-NEXT: Offset: 0x28
; YAML: - Type: DATA
; YAML: - Type: R_WASM_TABLE_INDEX_I64
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