Add new pass builder API

Author: rj45

passes.go

@@ -0,0 +1,129 @@
+package llvm
+
+/*
+#include "llvm-c/Transforms/PassBuilder.h"
+#include "llvm-c/Error.h"
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"errors"
+	"unsafe"
+)
+
+// PassBuilderOptions allows specifying several options for the PassBuilder.
+type PassBuilderOptions struct {
+	C C.LLVMPassBuilderOptionsRef
+}
+
+// NewPassBuilderOptions creates a PassBuilderOptions which can be used
+// to specify pass options for RunPasses.
+func NewPassBuilderOptions() (pbo PassBuilderOptions) {
+	pbo.C = C.LLVMCreatePassBuilderOptions()
+	return
+}
+
+// RunPasses runs the specified optimization passes on the functions in the module.
+// `passes` is a comma separated list of pass names in the same format as llvm's
+// `opt -passes=...` command. Running `opt -print-passes` can list the available
+// passes.
+//
+// Some notable passes include:
+//
+//	default<O0>  -- run the default -O0 passes
+//	default<O1>  -- run the default -O1 passes
+//	default<O2>  -- run the default -O2 passes
+//	default<O3>  -- run the default -O3 passes
+//	default<Os>  -- run the default -Os passes, like -O2 but size conscious
+//	default<Oz>  -- run the default -Oz passes, optimizing for size above all else
+func (mod Module) RunPasses(passes string, tm TargetMachine, options PassBuilderOptions) error {
+	cpasses := C.CString(passes)
+	defer C.free(unsafe.Pointer(cpasses))
+
+	err := C.LLVMRunPasses(mod.C, cpasses, tm.C, options.C)
+	if err != nil {
+		cstr := C.LLVMGetErrorMessage(err)
+		gstr := C.GoString(cstr)
+		C.LLVMDisposeErrorMessage(cstr)
+
+		return errors.New(gstr)
+	}
+	return nil
+}
+
+// SetVerifyEach toggles adding a VerifierPass to the PassBuilder,
+// ensuring all functions inside the module are valid. Useful for
+// debugging, but adds a significant amount of overhead.
+func (pbo PassBuilderOptions) SetVerifyEach(verifyEach bool) {
+	C.LLVMPassBuilderOptionsSetVerifyEach(pbo.C, boolToLLVMBool(verifyEach))
+}
+
+// SetDebugLogging toggles debug logging for the PassBuilder.
+func (pbo PassBuilderOptions) SetDebugLogging(debugLogging bool) {
+	C.LLVMPassBuilderOptionsSetDebugLogging(pbo.C, boolToLLVMBool(debugLogging))
+}
+
+// SetLoopInterleaving toggles loop interleaving, which is part of
+// loop vectorization.
+func (pbo PassBuilderOptions) SetLoopInterleaving(loopInterleaving bool) {
+	C.LLVMPassBuilderOptionsSetLoopInterleaving(pbo.C, boolToLLVMBool(loopInterleaving))
+}
+
+// SetLoopVectorization toggles loop vectorization.
+func (pbo PassBuilderOptions) SetLoopVectorization(loopVectorization bool) {
+	C.LLVMPassBuilderOptionsSetLoopVectorization(pbo.C, boolToLLVMBool(loopVectorization))
+}
+
+// SetSLPVectorization toggles Super-Word Level Parallelism vectorization,
+// whose goal is to combine multiple similar independent instructions into
+// a vector instruction.
+func (pbo PassBuilderOptions) SetSLPVectorization(slpVectorization bool) {
+	C.LLVMPassBuilderOptionsSetSLPVectorization(pbo.C, boolToLLVMBool(slpVectorization))
+}
+
+// SetLoopUnrolling toggles loop unrolling.
+func (pbo PassBuilderOptions) SetLoopUnrolling(loopUnrolling bool) {
+	C.LLVMPassBuilderOptionsSetLoopUnrolling(pbo.C, boolToLLVMBool(loopUnrolling))
+}
+
+// SetForgetAllSCEVInLoopUnroll toggles forgetting all SCEV (Scalar Evolution)
+// information in loop unrolling. Scalar Evolution is a pass that analyses
+// the how scalars evolve over iterations of a loop in order to optimize
+// the loop better. Forgetting this information can be useful in some cases.
+func (pbo PassBuilderOptions) SetForgetAllSCEVInLoopUnroll(forgetSCEV bool) {
+	C.LLVMPassBuilderOptionsSetForgetAllSCEVInLoopUnroll(pbo.C, boolToLLVMBool(forgetSCEV))
+}
+
+// SetLicmMssaOptCap sets a tuning option to cap the number of calls to
+// retrieve clobbering accesses in MemorySSA, in Loop Invariant Code Motion
+// optimization.
+// See [llvm::PipelineTuningOptions::LicmMssaOptCap].
+func (pbo PassBuilderOptions) SetLicmMssaOptCap(optCap uint) {
+	C.LLVMPassBuilderOptionsSetLicmMssaOptCap(pbo.C, C.unsigned(optCap))
+}
+
+// SetLicmMssaNoAccForPromotionCap sets a tuning option to cap the number of
+// promotions to scalars in Loop Invariant Code Motion with MemorySSA, if
+// the number of accesses is too large.
+// See [llvm::PipelineTuningOptions::LicmMssaNoAccForPromotionCap].
+func (pbo PassBuilderOptions) SetLicmMssaNoAccForPromotionCap(promotionCap uint) {
+	C.LLVMPassBuilderOptionsSetLicmMssaNoAccForPromotionCap(pbo.C, C.unsigned(promotionCap))
+}
+
+// SetCallGraphProfile toggles whether call graph profiling should be used.
+func (pbo PassBuilderOptions) SetCallGraphProfile(cgProfile bool) {
+	C.LLVMPassBuilderOptionsSetCallGraphProfile(pbo.C, boolToLLVMBool(cgProfile))
+}
+
+// SetMergeFunctions toggles finding functions which will generate identical
+// machine code by considering all pointer types to be equivalent. Once
+// identified, they will be folded by replacing a call to one with a call to a
+// bitcast of the other.
+func (pbo PassBuilderOptions) SetMergeFunctions(mergeFuncs bool) {
+	C.LLVMPassBuilderOptionsSetMergeFunctions(pbo.C, boolToLLVMBool(mergeFuncs))
+}
+
+// Dispose of the memory allocated for the PassBuilderOptions.
+func (pbo PassBuilderOptions) Dispose() {
+	C.LLVMDisposePassBuilderOptions(pbo.C)
+}

passes_test.go

@@ -0,0 +1,82 @@
+package llvm
+
+import "testing"
+
+func TestPasses(t *testing.T) {
+	InitializeNativeTarget()
+	InitializeNativeAsmPrinter()
+
+	ctx := NewContext()
+
+	mod := ctx.NewModule("fac_module")
+
+	fac_args := []Type{ctx.Int32Type()}
+	fac_type := FunctionType(ctx.Int32Type(), fac_args, false)
+	fac := AddFunction(mod, "fac", fac_type)
+	fac.SetFunctionCallConv(CCallConv)
+	n := fac.Param(0)
+
+	entry := AddBasicBlock(fac, "entry")
+	iftrue := AddBasicBlock(fac, "iftrue")
+	iffalse := AddBasicBlock(fac, "iffalse")
+	end := AddBasicBlock(fac, "end")
+
+	builder := ctx.NewBuilder()
+	defer builder.Dispose()
+
+	builder.SetInsertPointAtEnd(entry)
+	If := builder.CreateICmp(IntEQ, n, ConstInt(ctx.Int32Type(), 0, false), "cmptmp")
+	builder.CreateCondBr(If, iftrue, iffalse)
+
+	builder.SetInsertPointAtEnd(iftrue)
+	res_iftrue := ConstInt(ctx.Int32Type(), 1, false)
+	builder.CreateBr(end)
+
+	builder.SetInsertPointAtEnd(iffalse)
+	n_minus := builder.CreateSub(n, ConstInt(ctx.Int32Type(), 1, false), "subtmp")
+	call_fac_args := []Value{n_minus}
+	call_fac := builder.CreateCall(fac_type, fac, call_fac_args, "calltmp")
+	res_iffalse := builder.CreateMul(n, call_fac, "multmp")
+	builder.CreateBr(end)
+
+	builder.SetInsertPointAtEnd(end)
+	res := builder.CreatePHI(ctx.Int32Type(), "result")
+	phi_vals := []Value{res_iftrue, res_iffalse}
+	phi_blocks := []BasicBlock{iftrue, iffalse}
+	res.AddIncoming(phi_vals, phi_blocks)
+	builder.CreateRet(res)
+
+	err := VerifyModule(mod, ReturnStatusAction)
+	if err != nil {
+		t.Errorf("Error verifying module: %s", err)
+		return
+	}
+
+	targ, err := GetTargetFromTriple(DefaultTargetTriple())
+	if err != nil {
+		t.Error(err)
+	}
+
+	mt := targ.CreateTargetMachine(DefaultTargetTriple(), "", "", CodeGenLevelDefault, RelocDefault, CodeModelDefault)
+
+	pbo := NewPassBuilderOptions()
+	defer pbo.Dispose()
+
+	t.Run("no error running default pass", func(t *testing.T) {
+		err := mod.RunPasses("default<Os>", mt, pbo)
+		if err != nil {
+			t.Error(err)
+		}
+	})
+
+	t.Run("errors on unknown pass name", func(t *testing.T) {
+		err := mod.RunPasses("badpassnamedoesnotexist", mt, pbo)
+		if err == nil {
+			t.Error("expecting error but got none")
+		}
+
+		if err.Error() != "unknown pass name 'badpassnamedoesnotexist'" {
+			t.Errorf("expected error about unknow pass name, instead got %s", err)
+		}
+	})
+}