all: remove support for LLVM 11 and LLVM 12

This removes a lot of backwards compatibility cruft and makes it
possible to start using features that need LLVM 13 or newer.
For example:

  * https://github.com/tinygo-org/tinygo/pull/2637
  * https://github.com/tinygo-org/tinygo/pull/2830

.circleci/config.yml

@@ -102,21 +102,16 @@ commands:
       - run: make fmt-check
 
 jobs:
-  test-llvm11-go116:
+  test-llvm13-go116:
     docker:
       - image: circleci/golang:1.16-buster
     steps:
       - test-linux:
-          llvm: "11"
-  test-llvm12-go117:
-    docker:
-      - image: circleci/golang:1.17-buster
-    steps:
-      - test-linux:
-          llvm: "12"
+          llvm: "13"
 
 workflows:
   test-all:
     jobs:
-      - test-llvm11-go116
-      - test-llvm12-go117
+      # This tests our lowest supported versions of Go and LLVM, to make sure at
+      # least the smoke tests still pass.
+      - test-llvm13-go116

builder/build.go

@@ -935,17 +935,6 @@ func optimizeProgram(mod llvm.Module, config *compileopts.Config) error {
 		return errors.New("verification failure after LLVM optimization passes")
 	}
 
-	// LLVM 11 by default tries to emit tail calls (even with the target feature
-	// disabled) unless it is explicitly disabled with a function attribute.
-	// This is a problem, as it tries to emit them and prints an error when it
-	// can't with this feature disabled.
-	// Because as of september 2020 tail calls are not yet widely supported,
-	// they need to be disabled until they are widely supported (at which point
-	// the +tail-call target feautre can be set).
-	if strings.HasPrefix(config.Triple(), "wasm") {
-		transform.DisableTailCalls(mod)
-	}
-
 	return nil
 }
 

builder/builder_test.go

@@ -26,7 +26,7 @@ func TestClangAttributes(t *testing.T) {
 		"cortex-m0",
 		"cortex-m0plus",
 		"cortex-m3",
-		//"cortex-m33", // TODO: broken in LLVM 11, fixed in https://reviews.llvm.org/D90305
+		"cortex-m33",
 		"cortex-m4",
 		"cortex-m7",
 		"esp32c3",

builder/darwin-libsystem.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/goenv"
-	"tinygo.org/x/go-llvm"
 )
 
 // Create a job that builds a Darwin libSystem.dylib stub library. This library
@@ -39,12 +38,8 @@ func makeDarwinLibSystemJob(config *compileopts.Config, tmpdir string) *compileJ
 
 			// Link object file to dynamic library.
 			platformVersion := strings.TrimPrefix(strings.Split(config.Triple(), "-")[2], "macosx")
-			flavor := "darwin"
-			if strings.Split(llvm.Version, ".")[0] < "13" {
-				flavor = "darwinnew" // needed on LLVM 12 and below
-			}
 			flags = []string{
-				"-flavor", flavor,
+				"-flavor", "darwin",
 				"-demangle",
 				"-dynamic",
 				"-dylib",

builder/tools-builtin.go

@@ -54,7 +54,7 @@ func RunTool(tool string, args ...string) error {
 		ok = C.tinygo_clang_driver(C.int(len(args)), (**C.char)(buf))
 	case "ld.lld":
 		switch linker {
-		case "darwin", "darwinnew": // darwinnew is only needed for LLVM 12 and below
+		case "darwin":
 			ok = C.tinygo_link_macho(C.int(len(args)), (**C.char)(buf))
 		case "elf":
 			ok = C.tinygo_link_elf(C.int(len(args)), (**C.char)(buf))

cgo/libclang_config_llvm11.go

@@ -1,16 +0,0 @@
-//go:build !byollvm && llvm11
-// +build !byollvm,llvm11
-
-package cgo
-
-/*
-#cgo linux        CFLAGS:  -I/usr/lib/llvm-11/include
-#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@11/include
-#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@11/include
-#cgo freebsd      CFLAGS:  -I/usr/local/llvm11/include
-#cgo linux        LDFLAGS: -L/usr/lib/llvm-11/lib -lclang
-#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
-#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@11/lib -lclang -lffi
-#cgo freebsd      LDFLAGS: -L/usr/local/llvm11/lib -lclang
-*/
-import "C"

cgo/libclang_config_llvm12.go

@@ -1,16 +0,0 @@
-//go:build !byollvm && llvm12
-// +build !byollvm,llvm12
-
-package cgo
-
-/*
-#cgo linux        CFLAGS:  -I/usr/lib/llvm-12/include
-#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@12/include
-#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@12/include
-#cgo freebsd      CFLAGS:  -I/usr/local/llvm12/include
-#cgo linux        LDFLAGS: -L/usr/lib/llvm-12/lib -lclang
-#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@12/lib -lclang -lffi
-#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@12/lib -lclang -lffi
-#cgo freebsd      LDFLAGS: -L/usr/local/llvm12/lib -lclang
-*/
-import "C"

cgo/libclang_config_llvm13.go

@@ -1,5 +1,5 @@
-//go:build !byollvm && !llvm11 && !llvm12 && !llvm14
-// +build !byollvm,!llvm11,!llvm12,!llvm14
+//go:build !byollvm && !llvm14
+// +build !byollvm,!llvm14
 
 package cgo
 

compileopts/target.go

@@ -12,11 +12,9 @@ import (
 	"path/filepath"
 	"reflect"
 	"runtime"
-	"strconv"
 	"strings"
 
 	"github.com/tinygo-org/tinygo/goenv"
-	"tinygo.org/x/go-llvm"
 )
 
 // Target specification for a given target. Used for bare metal targets.
@@ -266,12 +264,8 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 		spec.Libc = "darwin-libSystem"
 		arch := strings.Split(triple, "-")[0]
 		platformVersion := strings.TrimPrefix(strings.Split(triple, "-")[2], "macosx")
-		flavor := "darwin"
-		if strings.Split(llvm.Version, ".")[0] < "13" {
-			flavor = "darwinnew" // needed on LLVM 12 and below
-		}
 		spec.LDFlags = append(spec.LDFlags,
-			"-flavor", flavor,
+			"-flavor", "darwin",
 			"-dead_strip",
 			"-arch", arch,
 			"-platform_version", "macos", platformVersion, platformVersion,
@@ -296,13 +290,8 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 			"--image-base", "0x400000",
 			"--gc-sections",
 			"--no-insert-timestamp",
+			"--no-dynamicbase",
 		)
-		llvmMajor, _ := strconv.Atoi(strings.Split(llvm.Version, ".")[0])
-		if llvmMajor >= 12 {
-			// This flag was added in LLVM 12. At the same time, LLVM 12
-			// switched the default from --dynamicbase to --no-dynamicbase.
-			spec.LDFlags = append(spec.LDFlags, "--no-dynamicbase")
-		}
 	} else {
 		spec.LDFlags = append(spec.LDFlags, "-no-pie", "-Wl,--gc-sections") // WARNING: clang < 5.0 requires -nopie
 	}

compiler/atomic.go

@@ -52,30 +52,6 @@ func (b *builder) createAtomicOp(call *ssa.CallCommon) (llvm.Value, bool) {
 		ptr := b.getValue(call.Args[0])
 		old := b.getValue(call.Args[1])
 		newVal := b.getValue(call.Args[2])
-		if strings.HasSuffix(name, "64") {
-			if strings.HasPrefix(b.Triple, "thumb") {
-				// Work around a bug in LLVM, at least LLVM 11:
-				// https://reviews.llvm.org/D95891
-				// Check for thumbv6m, thumbv7, thumbv7em, and perhaps others.
-				// See also: https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html
-				compareAndSwap := b.mod.NamedFunction("__sync_val_compare_and_swap_8")
-				if compareAndSwap.IsNil() {
-					// Declare the function if it isn't already declared.
-					i64Type := b.ctx.Int64Type()
-					fnType := llvm.FunctionType(i64Type, []llvm.Type{llvm.PointerType(i64Type, 0), i64Type, i64Type}, false)
-					compareAndSwap = llvm.AddFunction(b.mod, "__sync_val_compare_and_swap_8", fnType)
-				}
-				actualOldValue := b.CreateCall(compareAndSwap, []llvm.Value{ptr, old, newVal}, "")
-				// The __sync_val_compare_and_swap_8 function returns the old
-				// value. However, we shouldn't return the old value, we should
-				// return whether the compare/exchange was successful. This is
-				// easily done by comparing the returned (actual) old value with
-				// the expected old value passed to
-				// __sync_val_compare_and_swap_8.
-				swapped := b.CreateICmp(llvm.IntEQ, old, actualOldValue, "")
-				return swapped, true
-			}
-		}
 		tuple := b.CreateAtomicCmpXchg(ptr, old, newVal, llvm.AtomicOrderingSequentiallyConsistent, llvm.AtomicOrderingSequentiallyConsistent, true)
 		swapped := b.CreateExtractValue(tuple, 1, "")
 		return swapped, true

compiler/compiler_test.go

@@ -28,18 +28,11 @@ type testCase struct {
 func TestCompiler(t *testing.T) {
 	t.Parallel()
 
-	// Check LLVM version.
+	// Determine LLVM version.
 	llvmMajor, err := strconv.Atoi(strings.SplitN(llvm.Version, ".", 2)[0])
 	if err != nil {
 		t.Fatal("could not parse LLVM version:", llvm.Version)
 	}
-	if llvmMajor < 11 {
-		// It is likely this version needs to be bumped in the future.
-		// The goal is to at least test the LLVM version that's used by default
-		// in TinyGo and (if possible without too many workarounds) also some
-		// previous versions.
-		t.Skip("compiler tests require LLVM 11 or above, got LLVM ", llvm.Version)
-	}
 
 	// Determine Go minor version (e.g. 16 in go1.16.3).
 	_, goMinor, err := goenv.GetGorootVersion(goenv.Get("GOROOT"))
@@ -221,11 +214,6 @@ func filterIrrelevantIRLines(lines []string) []string {
 		if strings.HasPrefix(line, "source_filename = ") {
 			continue
 		}
-		if llvmVersion < 12 && strings.HasPrefix(line, "attributes ") {
-			// Ignore attribute groups. These may change between LLVM versions.
-			// Right now test outputs are for LLVM 12 and higher.
-			continue
-		}
 		if llvmVersion < 14 && strings.HasPrefix(line, "target datalayout = ") {
 			// The datalayout string may vary betewen LLVM versions.
 			// Right now test outputs are for LLVM 14 and higher.

src/runtime/gc_conservative.go

@@ -233,14 +233,6 @@ func setHeapEnd(newHeapEnd uintptr) {
 // This function can be called again when the heap size increases. The caller is
 // responsible for copying the metadata to the new location.
 func calculateHeapAddresses() {
-	if GOARCH == "wasm" {
-		// This is a workaround for a bug in wasm-ld: wasm-ld doesn't always
-		// align __heap_base and when this memory is shared through an API, it
-		// might result in unaligned memory. For details, see:
-		// https://reviews.llvm.org/D106499
-		// It should be removed once we switch to LLVM 13, where this is fixed.
-		heapStart = align(heapStart)
-	}
 	totalSize := heapEnd - heapStart
 
 	// Allocate some memory to keep 2 bits of information about every block.

src/runtime/gc_globals_conservative.go

@@ -4,21 +4,10 @@
 
 package runtime
 
-import "unsafe"
-
 // markGlobals marks all globals, which are reachable by definition.
 //
 // This implementation marks all globals conservatively and assumes it can use
 // linker-defined symbols for the start and end of the .data section.
 func markGlobals() {
-	end := globalsEnd
-	if GOARCH == "wasm" {
-		// This is a workaround for a bug in wasm-ld: wasm-ld doesn't always
-		// align __heap_base and when this memory is shared through an API, it
-		// might result in unaligned memory. For details, see:
-		// https://reviews.llvm.org/D106499
-		// It should be removed once we switch to LLVM 13, where this is fixed.
-		end = end &^ (unsafe.Alignof(end) - 1)
-	}
-	markRoots(globalsStart, end)
+	markRoots(globalsStart, globalsEnd)
 }

src/runtime/gc_leaking.go

@@ -67,12 +67,7 @@ func SetFinalizer(obj interface{}, finalizer interface{}) {
 
 func initHeap() {
 	// preinit() may have moved heapStart; reset heapptr
-	ptr := heapStart
-	if GOARCH == "wasm" {
-		// llvm11 and llvm12 do not correctly align the heap on wasm
-		ptr = align(ptr)
-	}
-	heapptr = ptr
+	heapptr = heapStart
 }
 
 // setHeapEnd sets a new (larger) heapEnd pointer.

targets/cortex-m33.json

@@ -1,4 +1,6 @@
 {
     "inherits": ["cortex-m"],
-    "llvm-target": "thumbv7m-unknown-unknown-eabi"
+    "llvm-target": "thumbv8m.main-unknown-unknown-eabi",
+    "cpu": "cortex-m33",
+    "features": "+armv8-m.main,+dsp,+hwdiv,+soft-float,+strict-align,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp"
 }

transform/globals.go

@@ -18,17 +18,3 @@ func ApplyFunctionSections(mod llvm.Module) {
 		llvmFn = llvm.NextFunction(llvmFn)
 	}
 }
-
-// DisableTailCalls adds the "disable-tail-calls"="true" function attribute to
-// all functions. This may be necessary, in particular to avoid an error with
-// WebAssembly in LLVM 11.
-func DisableTailCalls(mod llvm.Module) {
-	attribute := mod.Context().CreateStringAttribute("disable-tail-calls", "true")
-	llvmFn := mod.FirstFunction()
-	for !llvmFn.IsNil() {
-		if !llvmFn.IsDeclaration() {
-			llvmFn.AddFunctionAttr(attribute)
-		}
-		llvmFn = llvm.NextFunction(llvmFn)
-	}
-}

transform/transform_test.go

@@ -9,7 +9,6 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"strconv"
 	"strings"
 	"testing"
 
@@ -101,12 +100,6 @@ func fuzzyEqualIR(s1, s2 string) bool {
 // stripped out.
 func filterIrrelevantIRLines(lines []string) []string {
 	var out []string
-	llvmVersion, err := strconv.Atoi(strings.Split(llvm.Version, ".")[0])
-	if err != nil {
-		// Note: this should never happen and if it does, it will always happen
-		// for a particular build because llvm.Version is a constant.
-		panic(err)
-	}
 	for _, line := range lines {
 		line = strings.Split(line, ";")[0]    // strip out comments/info
 		line = strings.TrimRight(line, "\r ") // drop '\r' on Windows and remove trailing spaces from comments
@@ -116,11 +109,6 @@ func filterIrrelevantIRLines(lines []string) []string {
 		if strings.HasPrefix(line, "source_filename = ") {
 			continue
 		}
-		if llvmVersion < 12 && strings.HasPrefix(line, "attributes ") {
-			// Ignore attribute groups. These may change between LLVM versions.
-			// Right now test outputs are for LLVM 12.
-			continue
-		}
 		out = append(out, line)
 	}
 	return out