const (
	leaveDeadValues  deadValueChoice = false
	removeDeadValues                 = true
)

// deadcode indicates whether rewrite should try to remove any values that become dead.
func applyRewrite(f *Func, rb blockRewriter, rv valueRewriter, deadcode deadValueChoice) {
	// repeat rewrites until we find no more rewrites
	pendingLines := f.cachedLineStarts // Holds statement boundaries that need to be moved to a new value/block
	pendingLines.clear()

                          ArrayRef<int64_t> shape, int64_t val) {
  RankedTensorType type =
      tensorflow::GetTypeFromTFTensorShape(shape, rewriter->getIntegerType(64));
  DenseElementsAttr attr =
      DenseElementsAttr::get(type, rewriter->getI64IntegerAttr(val));
  return rewriter->create<arith::ConstantOp>(loc, type, attr);
}

Value CreateI32SplatTensor(Location loc, PatternRewriter *rewriter,

    // Erase unused ops after the transformation.
    rewriter.eraseOp(output_uniform_dequantize_call_pattern->GetCallOp());
    rewriter.eraseOp(output_uniform_quantize_call_pattern->GetCallOp());
    rewriter.eraseOp(multiply_op);
    rewriter.eraseOp(subtract_op);
    rewriter.eraseOp(input_i8_to_f32_convert_op);
    rewriter.eraseOp(input_uniform_quantize_call_pattern->GetCallOp());
  }

				needsUnsafe = true
			}
		}
	}
	return needsUnsafe
}

// rewriteCall rewrites one call to add pointer checks.
// If any pointer checks are required, we rewrite the call into a
// function literal that calls _cgoCheckPointer for each pointer
// argument and then calls the original function.
// This returns the rewritten call and whether the package needs to
// import unsafe as _cgo_unsafe.

  %identity = "tf.Identity"(%arg0) : (tensor<i32>) -> tensor<i32>
  return %identity : tensor<i32>
}
```
### `-tf-tpu-rewrite`

_Rewrites a `tf_device.cluster_func` on TPUs into TPU runtime operations._

This pass rewrites a `tf_device.cluster_func` operation into a sequence of `tf._TPUCompileMlir`
and `tf.TPUExecute` operations. `tf._TPUCompileMlir` contains a MLIR module that is

	//TODO: this compiles to add r5,r6,r0. It should be addi r5,r6,0.
	//      this is OK since r0 == $0, but the latter is preferred.
	ADD $0, R6, R5             	// 7ca60214

        //TODO: the assembler rewrites these into ADDIS $19, R5, Rx and ADD $-10617, Rx, Rx, but the test only sees the first ADDIS
	ADD $1234567, R5                // 3ca50013 or 0600001238a5d687
	ADD $1234567, R5, R6            // 3cc50013 or 0600001238c5d687

	// stubs and reserve a PLT slot.
	//
	// 1) The call site is a "bl x" where genpltstub rewrites it to
	//    "bl x_stub". Depending on the properties of the caller
	//    (see ELFv2 1.5 4.2.5.3), a nop may be expected immediately
	//    after the bl. This nop is rewritten to ld r2,24(r1) to
	//    restore the toc pointer saved by x_stub.
	//

(MOVBstore [off] {sym} ptr y:(SETA x) mem) && y.Uses == 1 => (SETAstore [off] {sym} ptr x mem)
(MOVBstore [off] {sym} ptr y:(SETAE x) mem) && y.Uses == 1 => (SETAEstore [off] {sym} ptr x mem)

// block rewrites
(If (SETL  cmp) yes no) => (LT  cmp yes no)
(If (SETLE cmp) yes no) => (LE  cmp yes no)
(If (SETG  cmp) yes no) => (GT  cmp yes no)
(If (SETGE cmp) yes no) => (GE  cmp yes no)
(If (SETEQ cmp) yes no) => (EQ  cmp yes no)

	fgcc := creat(*objDir + base + ".cgo2.c")

	p.GoFiles = append(p.GoFiles, base+".cgo1.go")
	p.GccFiles = append(p.GccFiles, base+".cgo2.c")

	// Write Go output: Go input with rewrites of C.xxx to _C_xxx.
	fmt.Fprintf(fgo1, "// Code generated by cmd/cgo; DO NOT EDIT.\n\n")
	if strings.ContainsAny(srcfile, "\r\n") {
		// This should have been checked when the file path was first resolved,

			p.print(token.CHAN)
			p.setPos(x.Arrow)
			p.print(token.ARROW)
		}
		p.print(blank)
		p.expr(x.Value)

	default:
		panic("unreachable")
	}
}

// normalizedNumber rewrites base prefixes and exponents
// of numbers to use lower-case letters (0X123 to 0x123 and 1.2E3 to 1.2e3),
// and removes leading 0's from integer imaginary literals (0765i to 765i).
// It leaves hexadecimal digits alone.